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path: root/drivers/usb/host/xhci.c
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2026-03-19usb: xhci: Fix memory leak in xhci_disable_slot()Zilin Guan
commit c1c8550e70401159184130a1afc6261db01fc0ce upstream. xhci_alloc_command() allocates a command structure and, when the second argument is true, also allocates a completion structure. Currently, the error handling path in xhci_disable_slot() only frees the command structure using kfree(), causing the completion structure to leak. Use xhci_free_command() instead of kfree(). xhci_free_command() correctly frees both the command structure and the associated completion structure. Since the command structure is allocated with zero-initialization, command->in_ctx is NULL and will not be erroneously freed by xhci_free_command(). This bug was found using an experimental static analysis tool we are developing. The tool is based on the LLVM framework and is specifically designed to detect memory management issues. It is currently under active development and not yet publicly available, but we plan to open-source it after our research is published. The bug was originally detected on v6.13-rc1 using our static analysis tool, and we have verified that the issue persists in the latest mainline kernel. We performed build testing on x86_64 with allyesconfig using GCC=11.4.0. Since triggering these error paths in xhci_disable_slot() requires specific hardware conditions or abnormal state, we were unable to construct a test case to reliably trigger these specific error paths at runtime. Fixes: 7faac1953ed1 ("xhci: avoid race between disable slot command and host runtime suspend") CC: stable@vger.kernel.org Signed-off-by: Zilin Guan <zilin@seu.edu.cn> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://patch.msgid.link/20260304223639.3882398-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-23xhci: sideband: don't dereference freed ring when removing sideband endpointMathias Nyman
commit dd83dc1249737b837ac5d57c81f2b0977c613d9f upstream. xhci_sideband_remove_endpoint() incorrecly assumes that the endpoint is running and has a valid transfer ring. Lianqin reported a crash during suspend/wake-up stress testing, and found the cause to be dereferencing a non-existing transfer ring 'ep->ring' during xhci_sideband_remove_endpoint(). The endpoint and its ring may be in unknown state if this function is called after xHCI was reinitialized in resume (lost power), or if device is being re-enumerated, disconnected or endpoint already dropped. Fix this by both removing unnecessary ring access, and by checking ep->ring exists before dereferencing it. Also make sure endpoint is running before attempting to stop it. Remove the xhci_initialize_ring_info() call during sideband endpoint removal as is it only initializes ring structure enqueue, dequeue and cycle state values to their starting values without changing actual hardware enqueue, dequeue and cycle state. Leaving them out of sync is worse than leaving it as it is. The endpoint will get freed in after this in most usecases. If the (audio) class driver want's to reuse the endpoint after offload then it is up to the class driver to ensure endpoint is properly set up. Reported-by: 胡连勤 <hulianqin@vivo.com> Closes: https://lore.kernel.org/linux-usb/TYUPR06MB6217B105B059A7730C4F6EC8D2B9A@TYUPR06MB6217.apcprd06.prod.outlook.com/ Tested-by: 胡连勤 <hulianqin@vivo.com> Fixes: de66754e9f80 ("xhci: sideband: add initial api to register a secondary interrupter entity") Cc: stable@vger.kernel.org Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://patch.msgid.link/20260115233758.364097-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-09xhci: fix stale flag preventig URBs after link state error is clearedMathias Nyman
A usb device caught behind a link in ss.Inactive error state needs to be reset to recover. A VDEV_PORT_ERROR flag is used to track this state, preventing new transfers from being queued until error is cleared. This flag may be left uncleared if link goes to error state between two resets, and print the following message: "xhci_hcd 0000:00:14.0: Can't queue urb, port error, link inactive" Fix setting and clearing the flag. The flag is cleared after hub driver has successfully reset the device when hcd->reset_device is called. xhci-hcd issues an internal "reset device" command in this callback, and clear all flags once the command completes successfully. This command may complete with a context state error if slot was recently reset and is already in the defauilt state. This is treated as a success but flag was left uncleared. The link state field is also unreliable if port is currently in reset, so don't set the flag in active reset cases. Also clear the flag immediately when link is no longer in ss.Inactive state and port event handler detects a completed reset. This issue was discovered while debugging kernel bugzilla issue 220491. It is likely one small part of the problem, causing some of the failures, but root cause remains unknown Link: https://bugzilla.kernel.org/show_bug.cgi?id=220491 Fixes: b8c3b718087b ("usb: xhci: Don't try to recover an endpoint if port is in error state.") Cc: stable@vger.kernel.org Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://patch.msgid.link/20251107162819.1362579-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-06Merge patch series "eUSB2 Double Isochronous IN Bandwidth support"Greg Kroah-Hartman
Sakari Ailus <sakari.ailus@linux.intel.com> says: This series enables support for eUSB2 Double Isochronous IN Bandwidth UVC devices specified in 'USB 2.0 Double Isochronous IN Bandwidth' ECN. In short, it adds support for new integrated USB2 webcams that can send twice the data compared to conventional USB2 webcams. These devices are identified by the device descriptor bcdUSB 0x0220 value. They have an additional eUSB2 Isochronous Endpoint Companion Descriptor, and a zero max packet size in regular isoc endpoint descriptor. Support for parsing that new descriptor was added in commit c749f058b437 ("USB: core: Add eUSB2 descriptor and parsing in USB core") This series adds support to UVC, USB core, and xHCI to identify eUSB2 double isoc devices, and allow and set proper max packet, iso frame desc sizes, bytes per interval, and other values in URBs and xHCI endpoint contexts needed to support the double data rates for eUSB2 double isoc devices. since v4: https://lore.kernel.org/linux-usb/20250812132445.3185026-1-sakari.ailus@linux.intel.com - New patch: use le16_to_cpu() to access endpoint descriptor's wMaxPacketSize field, which is an __le16. This isn't a bugfix as the value was compared to 0. - New patch: add USB device speed check for eUSB2 isochronous endpoint companion parsing. The check is then removed from sites checking the existence of the companion (through companion's bDescriptorType field, which is non-zero for valid descriptors). - New patch: do not parse eUSB2 isoc double BW companion descriptor on interrupt or OUT endpoints. It is not supposed to be found there, according to the ECN. - Rename usb_endpoint_max_isoc_bpi() as usb_endpoint_max_periodic_payload() and move it right after usb_maxpacket(). - Fixed @ep reference in kernel-doc documentation for usb_endpoint_max_periodic_payload(). - In usb_endpoint_max_periodic_payload(), call struct usb_device pointer argument "udev" instead of "dev", to align with naming elsewhere. - Add support for interrupt endpoints in usb_endpoint_max_periodic_payload(); eUSB2 double isoc BW is still limited to isochronous endpoints though. - In usb_endpoint_max_periodic_payload(), remove the separate case for USB_SPEED_HIGH as the check is already done in parsing the eUSB isoc double BW companion, which is checked for. - New patch: use usb_endpoint_max_periodic_payload() in xHCI driver, replacing xhci_get_max_esit_payload(). - Check non-zero bDescriptorType field of ep->eusb2_isoc_ep_comp instead of dwBytesPerInterval value exceeding 3072, where xhci_eusb2_is_isoc_bw_double() was used. This aligns the checks of eUSB2 isochronous double bandwidth support for an endpoint. - New patch: introduce usb_endpoint_is_hs_isoc_double() to figure out whether an endpoint uses isochronous double bandwidth and use the function in the xHCI driver and the usb core. xhci_eusb2_is_isoc_bw_double() is dropped, as well as the MAX_ISOC_XFER_SIZE_HS macro. usb_endpoint_is_hs_isoc_double() also includes check for bcdUSB == 0x220, to anticipate adding support for eUSB2V2. - Merge condition for checking eUSB2 isoc double bw support for xHCI/endpoint in xhci_get_endpoint_mult(). - Improve comment regarding maximum packet size bits 12:11 in xhci_get_endpoint_max_burst(). - Aligned subject prefixes with the recent patches to the same files. since v3: https://lore.kernel.org/linux-usb/20250807055355.1257029-1-sakari.ailus@linux.intel.com/ - Use spaces in aligning macro body for HCC2_EUSB2_DIC() (1st patch). - Move usb_endpoint_max_isoc_bpi() to drivers/usb/core/usb.c (3rd patch). since v2: https://lore.kernel.org/linux-usb/20250711083413.1552423-1-sakari.ailus@linux.intel.com - Use ep->eusb2_isoc_ep_comp.bDescriptorType to determined whether the eUSB2 isochronous endpoint companion descriptor exists. - Clean up eUSB2 double isoc bw maxp calculation. - Drop le16_to_cpu(udev->descriptor.bcdUSB) == 0x220 check from xhci_eusb2_is_isoc_bw_double() -- it's redundant as ep->eusb2_isoc_ep_comp.dwBytesPerInterval will be zero otherwise. - Add kernel-doc documentation for usb_endpoint_max_isoc_bpi(). - Check the endpoint has IN direction in usb_endpoint_max_isoc_bpi() and usb_submit_urb() as a condition for eUSB2 isoc double bw. since v1: https://lore.kernel.org/linux-usb/20250616093730.2569328-2-mathias.nyman@linux.intel.com - Introduce uvc_endpoint_max_isoc_bpi() to obtain maximum bytes per interval value for an endpoint, in a new patch (3rd). This code has been slightly reworked from the instance in the UVC driver, including support for SuperSpeedPlus Isochronous Endpoint Companion. - Use usb_endpoint_max_isoc_bpi() in the UVC driver instead of open-coding eUSB2 support there, also drop now-redundant uvc_endpoint_max_bpi(). - Use u32 for maximum bpi and related information in the UVC driver -- the value could be larger than a 16-bit type can hold. - Assume max in usb_submit_urb() is a natural number as usb_endpoint_maxp() returns only natural numbers (2nd patch). Link: https://lore.kernel.org/r/20250820143824.551777-1-sakari.ailus@linux.intel.com Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-06usb: xhci: Add host support for eUSB2 double isochronous bandwidth devicesRai, Amardeep
Detect eUSB2 double isoc bw capable hosts and devices, and set the proper xhci endpoint context values such as 'Mult', 'Max Burst Size', and 'Max ESIT Payload' to enable the double isochronous bandwidth endpoints. Intel xHC uses the endpoint context 'Mult' field for eUSB2 isoc endpoints even if hosts supporting Large ESIT Payload Capability should normally ignore the mult field. Signed-off-by: Rai, Amardeep <amardeep.rai@intel.com> Co-developed-by: Kannappan R <r.kannappan@intel.com> Signed-off-by: Kannappan R <r.kannappan@intel.com> Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com> Co-developed-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Co-developed-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20250820143824.551777-8-sakari.ailus@linux.intel.com
2025-08-19usb: xhci: fix host not responding after suspend and resumeNiklas Neronin
Partially revert commit e1db856bd288 ("usb: xhci: remove '0' write to write-1-to-clear register") because the patch cleared the Interrupt Pending bit during interrupt enabling and disabling. The Interrupt Pending bit should only be cleared when the driver has handled the interrupt. Ideally, all interrupts should be handled before disabling the interrupt; consequently, no interrupt should be pending when enabling the interrupt. For this reason, keep the debug message informing if an interrupt is still pending when an interrupt is disabled. Because the Interrupt Pending bit is write-1-to-clear, writing '0' to it ensures that the state does not change. Link: https://lore.kernel.org/linux-usb/20250818231103.672ec7ed@foxbook Fixes: e1db856bd288 ("usb: xhci: remove '0' write to write-1-to-clear register") Closes: https://bbs.archlinux.org/viewtopic.php?id=307641 cc: stable@vger.kernel.org # 6.16+ Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250819125844.2042452-3-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-19usb: xhci: Fix slot_id resource race conflictWeitao Wang
xHC controller may immediately reuse a slot_id after it's disabled, giving it to a new enumerating device before the xhci driver freed all resources related to the disabled device. In such a scenario, device-A with slot_id equal to 1 is disconnecting while device-B is enumerating, device-B will fail to enumerate in the follow sequence. 1.[device-A] send disable slot command 2.[device-B] send enable slot command 3.[device-A] disable slot command completed and wakeup waiting thread 4.[device-B] enable slot command completed with slot_id equal to 1 and wakeup waiting thread 5.[device-B] driver checks that slot_id is still in use (by device-A) in xhci_alloc_virt_device, and fail to enumerate due to this conflict 6.[device-A] xhci->devs[slot_id] set to NULL in xhci_free_virt_device To fix driver's slot_id resources conflict, clear xhci->devs[slot_id] and xhci->dcbba->dev_context_ptrs[slot_id] pointers in the interrupt context when disable slot command completes successfully. Simultaneously, adjust function xhci_free_virt_device to accurately handle device release. [minor smatch warning and commit message fix -Mathias] Cc: stable@vger.kernel.org Fixes: 7faac1953ed1 ("xhci: avoid race between disable slot command and host runtime suspend") Signed-off-by: Weitao Wang <WeitaoWang-oc@zhaoxin.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250819125844.2042452-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-17usb: xhci: Avoid showing warnings for dying controllerMario Limonciello
When a USB4 dock is unplugged from a system it won't respond to ring events. The PCI core handles the surprise removal event and notifies all PCI drivers. The XHCI PCI driver sets a flag that the device is being removed, and when the device stops responding a flag is also added to indicate it's dying. When that flag is set don't bother to show warnings about a missing controller. Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250717073107.488599-3-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-19Revert "usb: xhci: Implement xhci_handshake_check_state() helper"Roy Luo
This reverts commit 6ccb83d6c4972ebe6ae49de5eba051de3638362c. Commit 6ccb83d6c497 ("usb: xhci: Implement xhci_handshake_check_state() helper") was introduced to workaround watchdog timeout issues on some platforms, allowing xhci_reset() to bail out early without waiting for the reset to complete. Skipping the xhci handshake during a reset is a dangerous move. The xhci specification explicitly states that certain registers cannot be accessed during reset in section 5.4.1 USB Command Register (USBCMD), Host Controller Reset (HCRST) field: "This bit is cleared to '0' by the Host Controller when the reset process is complete. Software cannot terminate the reset process early by writinga '0' to this bit and shall not write any xHC Operational or Runtime registers until while HCRST is '1'." This behavior causes a regression on SNPS DWC3 USB controller with dual-role capability. When the DWC3 controller exits host mode and removes xhci while a reset is still in progress, and then tries to configure its hardware for device mode, the ongoing reset leads to register access issues; specifically, all register reads returns 0. These issues extend beyond the xhci register space (which is expected during a reset) and affect the entire DWC3 IP block, causing the DWC3 device mode to malfunction. Cc: stable <stable@kernel.org> Fixes: 6ccb83d6c497 ("usb: xhci: Implement xhci_handshake_check_state() helper") Signed-off-by: Roy Luo <royluo@google.com> Link: https://lore.kernel.org/r/20250522190912.457583-3-royluo@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-19usb: xhci: Skip xhci_reset in xhci_resume if xhci is being removedRoy Luo
xhci_reset() currently returns -ENODEV if XHCI_STATE_REMOVING is set, without completing the xhci handshake, unless the reset completes exceptionally quickly. This behavior causes a regression on Synopsys DWC3 USB controllers with dual-role capabilities. Specifically, when a DWC3 controller exits host mode and removes xhci while a reset is still in progress, and then attempts to configure its hardware for device mode, the ongoing, incomplete reset leads to critical register access issues. All register reads return zero, not just within the xHCI register space (which might be expected during a reset), but across the entire DWC3 IP block. This patch addresses the issue by preventing xhci_reset() from being called in xhci_resume() and bailing out early in the reinit flow when XHCI_STATE_REMOVING is set. Cc: stable <stable@kernel.org> Fixes: 6ccb83d6c497 ("usb: xhci: Implement xhci_handshake_check_state() helper") Suggested-by: Mathias Nyman <mathias.nyman@intel.com> Signed-off-by: Roy Luo <royluo@google.com> Link: https://lore.kernel.org/r/20250522190912.457583-2-royluo@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-08treewide, timers: Rename from_timer() to timer_container_of()Ingo Molnar
Move this API to the canonical timer_*() namespace. [ tglx: Redone against pre rc1 ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com
2025-05-21xhci: Add missing parameter description to xhci_get_endpoint_index()Hans Zhang
Fix kernel-doc warning by documenting the @desc parameter: drivers/usb/host/xhci.c:1369: warning: Function parameter or struct member 'desc' not described in 'xhci_get_endpoint_index' Add detailed description of the @desc parameter and clarify the indexing logic for control endpoints vs other types. This brings the documentation in line with kernel-doc requirements while maintaining technical accuracy. Signed-off-by: Hans Zhang <18255117159@163.com> Link: https://lore.kernel.org/r/20250506033101.206180-1-18255117159@163.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21usb: xhci: rename 'irq_control' to 'imod'Niklas Neronin
The Interrupt Register Set contains Interrupt Moderation register (IMOD). The IMOD register contains the following fields: - Bits 15:0: Interrupt Moderation Interval (IMODI) - Bits 31:16: Interrupt Moderation Counter (IMODC) In the xHCI driver, the pointer currently named 'irq_control' refers to the IMOD register. However, the name 'irq_control' does not accurately describe the register or its contents, and the xHCI specification does not use the term "irq control" or "interrupt control" for this register. To improve clarity and better align with the xHCI specification, the pointer is renamed to 'imod'. Additionally, the IMOD register fields IMODI & IMODC have their own masks, which are also renamed for consistency: * 'ER_IRQ_INTERVAL_MASK' -> 'IMODI_MASK' * 'ER_IRQ_COUNTER_MASK' -> 'IMODC_MASK' Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250515135621.335595-23-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21usb: xhci: rename 'irq_pending' to 'iman'Niklas Neronin
The Interrupt Register Set contains Interrupt Management register (IMAN). The IMAN register contains the following fields: - Bit 0: Interrupt Pending (IP) - Bit 1: Interrupt Enable (IE) - Bits 31:2: RsvdP (Reserved and Preserved) Tn the xhci driver, the pointer currently named 'irq_pending' refers to the IMAN register. However, the name "irq_pending" only describes one of the fields within the IMAN register, rather than the entire register itself. To improve clarity and better align with the xHCI specification, the pointer is renamed to 'iman'. Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250515135621.335595-22-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21usb: xhci: remove '0' write to write-1-to-clear registerNiklas Neronin
xHCI specification 1.2, section 5.5.2.1. Interrupt Pending bit is RW1C (Write-1-to-clear), which means that writing '0' to is has no effect and is removed. The Interrupt Pending (IP) bit is cleared at the start of interrupt handling; xhci_clear_interrupt_pending(). This could theoretically cause a new interrupt to be issued before the xhci driver reaches the interrupter disable functions. To address this, the IP bit is read after Interrupt Enable is disabled, and a debug message is issued if the IP bit is still set. Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250515135621.335595-18-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21usb: xhci: guarantee that IMAN register is flushedNiklas Neronin
Add read call to guarantee that the write to the IMAN register has been flushed. xHCI specification 1.2, section 5.5.2.1, Note: "Most systems have write buffers that minimize overhead, but this may require a read operation to guarantee that the write has been flushed from the posted buffer." Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250515135621.335595-17-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21usb: xhci: improve Interrupt Management register macrosNiklas Neronin
The Interrupt Management register (IMAN), contains three fields: - Bit 0: Interrupt Pending (IP) - Bit 1: Interrupt Enable (IE) - Bits 31:2: RsvdP (Reserved and Preserved) Currently, there are multiple macros for both the IP and IE fields. Consolidates them into single mask macros for better clarity and maintainability. Comment "THIS IS BUGGY - FIXME - IP IS WRITE 1 TO CLEAR" refers to the fact that both macros 'ER_IRQ_ENABLE' and 'ER_IRQ_DISABLE' clear the IP bit by writing '0' before modifying the IE bit. However, the IP bit is actually cleared by writing '1'. To prevent any regression, this behavior has not been altered. Instead, when the IE bit is modified, the IP macro is used explicitly to highlight this "quirk". Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250515135621.335595-16-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21usb: xhci: set requested IMODI to the closest supported valueNiklas Neronin
The function configures the Interrupt Moderation Interval (IMODI) via bits 15:0 in the Interrupt Moderation Register. The IMODI value is specified in increments of 250 nanoseconds. For instance, an IMODI register value of 16 corresponds to 4000 nanoseconds, resulting in an interrupt every ~1ms. Currently, the function fails when a requested IMODI value is too large, only logging a warning message for secondary interrupters. Prevent this by automatically adjusting the IMODI value to the nearest supported value. Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250515135621.335595-15-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21usb: xhci: move initialization of the primary interrupterNiklas Neronin
Move the primary interrupter (0) initialization from xhci_mem_init() to xhci_init(). This change requires us to save the allocated interrupter somewhere before initialization. Therefore, store it in the 'interrupters' array and rework xhci_add_interrupter() to retrieve the interrupter from the array. This is part of the ongoing effort to separate allocation and initialization. Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250515135621.335595-12-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21usb: xhci: move enabling of USB 3 device notificationsNiklas Neronin
Relocated the enabling of USB 3.0 device notifications from xhci_mem_init() to xhci_init(). Introduced xhci_set_dev_notifications() function to handle the notification settings. Simplify 'DEV_NOTE_FWAKE' masks by directly using the 'ENABLE_DEV_NOTE' value (1 << 1) instead of using the 'ENABLE_DEV_NOTE' macro. Macro 'ENABLE_DEV_NOTE' is removed. Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250515135621.335595-10-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21usb: xhci: move doorbell array pointer assignmentNiklas Neronin
Move the assignment of the doorbell array pointer from xhci_mem_init() to xhci_init(). The assignment now utilizes the newly introduced xhci_set_doorbell_ptr() function. Doorbell Array Offset mask (DBOFF_MASK) is updated to directly specify its bit range as 31:2, rather than using inverted reserved bits 1:0. This change simplifies the mask representation, making it more intuitive and easier to understand. Remove the "// " prefix from trace messages, as it is unnecessary and distracting. Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250515135621.335595-9-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21usb: xhci: move DCBAA pointer writeNiklas Neronin
Move the Device Context Base Address Array (DCBAA) pointer write from xhci_mem_init() to xhci_init(). This is part of the ongoing effort to separate allocation and initialization. Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250515135621.335595-8-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21usb: xhci: refactor xhci_set_cmd_ring_deq()Niklas Neronin
Refactor xhci_set_cmd_ring_deq() making the code more understandable by using more descriptive constants and separating operations logically. - Remove 'CMD_RING_RSVD_BITS' the macro is misleading, the reserved bits are 5:4, yet the mask is for bits 5:0. - Introduce masks 'CMD_RING_PTR_MASK' and 'CMD_RING_CYCLE' to clearly define the bits for the Command Ring pointer and Command Ring Cycle. - Simplifying the process of setting the command ring address by separating the DMA address calculation and the Command Ring Control register (crcr) updates. - Remove the "// " prefix from trace messages, as it is unnecessary and distracting. Note: In the current implementation, the cycle bit is not cleared before applying the OR operation. Although this hasn't caused issues so far because the bit is '0' before reaching this function, the bit is now cleared before being set to prevent potential future problems and simplify the process. Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250515135621.335595-7-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21usb: xhci: move command ring pointer writeNiklas Neronin
Move command ring pointer write from xhci_mem_init() to xhci_init(), and utilize the xhci_set_cmd_ring_deq() function. The xhci_set_cmd_ring_deq() function is nearly identical to the Command Ring Control register code in xhci_mem_init(). The only notable change is the use of: xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg, xhci->cmd_ring->dequeue) instead of: xhci->cmd_ring->first_seg->dma but they are effectively the same in this context. The former represents the exact position of the dequeue pointer, while the latter is the first DMA in the first segment. Before use, the dequeue pointer is at the first DMA in the first segment. The xhci_set_cmd_ring_deq() function is moved without modification, except for (long unsigned long) -> (unsigned long long) due to checkpatch.pl. Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250515135621.335595-6-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21usb: xhci: move device slot enabling register writeNiklas Neronin
Refactor the setting of the Number of Device Slots Enabled field into a separate function, relocating it to xhci_init(). The xHCI driver consistently sets the number of enabled device slots to the maximum value. The new function is named to reflect this behavior. Remove the "// " prefix from trace messages, as it is unnecessary and distracting. Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250515135621.335595-5-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21usb: xhci: relocate pre-allocation initializationNiklas Neronin
Move pre-allocation initialization from xhci_mem_init() to xhci_init(). This change is part of an ongoing effort to separate initialization from allocation within the xhci driver. By doing so, it will enable future patches to re-initialize xhci driver memory without the necessity of fully recreating it. Additionally, compliance mode recovery initialization has been adjusted to only occur after successful memory allocation. Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250515135621.335595-4-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-21usb: xhci: Add debugfs support for xHCI port bandwidthXu Rao
In many projects, you need to obtain the available bandwidth of the xhci roothub port. Refer to xhci rev1_2 and use the TRB_GET_BW command to obtain it. hardware tested: 03:00.3 USB controller: Advanced Micro Devices, Inc. [AMD] Raven USB 3.1 (prog-if 30 [XHCI]) Subsystem: Huawei Technologies Co., Ltd. Raven USB 3.1 Flags: bus master, fast devsel, latency 0, IRQ 30 Memory at c0300000 (64-bit, non-prefetchable) [size=1M] Capabilities: [48] Vendor Specific Information: Len=08 <?> Capabilities: [50] Power Management version 3 Capabilities: [64] Express Endpoint, MSI 00 Capabilities: [a0] MSI: Enable- Count=1/8 Maskable- 64bit+ Capabilities: [c0] MSI-X: Enable+ Count=8 Masked- Kernel driver in use: xhci_hcd test progress: 1. cd /sys/kernel/debug/usb/xhci/0000:03:00.3/port_bandwidth# ls FS_BW HS_BW SS_BW 2. test fs speed device cat FS_BW port[1] available bw: 90%. port[2] available bw: 90%. port[3] available bw: 90%. port[4] available bw: 90%. port[5] available bw: 0%. port[6] available bw: 0%. port[7] available bw: 0%. port[8] available bw: 0%. plug in fs usb audio ID 0d8c:013c cat FS_BW port[1] available bw: 76%. port[2] available bw: 76%. port[3] available bw: 76%. port[4] available bw: 76%. port[5] available bw: 0%. port[6] available bw: 0%. port[7] available bw: 0%. port[8] available bw: 0%. 3. test hs speed device cat HS_BW port[1] available bw: 79%. port[2] available bw: 79%. port[3] available bw: 79%. port[4] available bw: 79%. port[5] available bw: 0%. port[6] available bw: 0%. port[7] available bw: 0%. port[8] available bw: 0%. plug in hs usb video ID 0408:1040 cat HS_BW port[1] available bw: 39%. port[2] available bw: 39%. port[3] available bw: 39%. port[4] available bw: 39%. port[5] available bw: 0%. port[6] available bw: 0%. port[7] available bw: 0%. port[8] available bw: 0%. 4.cat SS_BW port[1] available bw: 0%. port[2] available bw: 0%. port[3] available bw: 0%. port[4] available bw: 0%. port[5] available bw: 90%. port[6] available bw: 90%. port[7] available bw: 90%. port[8] available bw: 90%. Signed-off-by: Xu Rao <raoxu@uniontech.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250515135621.335595-3-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-28Merge 6.15-rc4 into usb-nextGreg Kroah-Hartman
We need the USB fixes in here as well, and this resolves the following merge conflicts that were reported in linux-next: drivers/usb/chipidea/ci_hdrc_imx.c drivers/usb/host/xhci.h Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-11xhci: Limit time spent with xHC interrupts disabled during bus resumeMathias Nyman
Current xhci bus resume implementation prevents xHC host from generating interrupts during high-speed USB 2 and super-speed USB 3 bus resume. Only reason to disable interrupts during bus resume would be to prevent the interrupt handler from interfering with the resume process of USB 2 ports. Host initiated resume of USB 2 ports is done in two stages. The xhci driver first transitions the port from 'U3' to 'Resume' state, then wait in Resume for 20ms, and finally moves port to U0 state. xhci driver can't prevent interrupts by keeping the xhci spinlock due to this 20ms sleep. Limit interrupt disabling to the USB 2 port resume case only. resuming USB 2 ports in bus resume is only done in special cases where USB 2 ports had to be forced to suspend during bus suspend. The current way of preventing interrupts by clearing the 'Interrupt Enable' (INTE) bit in USBCMD register won't prevent the Interrupter registers 'Interrupt Pending' (IP), 'Event Handler Busy' (EHB) and USBSTS register Event Interrupt (EINT) bits from being set. New interrupts can't be issued before those bits are properly clered. Disable interrupts by clearing the interrupter register 'Interrupt Enable' (IE) bit instead. This way IP, EHB and INTE won't be set before IE is enabled again and a new interrupt is triggered. Reported-by: Devyn Liu <liudingyuan@huawei.com> Closes: https://lore.kernel.org/linux-usb/b1a9e2d51b4d4ff7a304f77c5be8164e@huawei.com/ Cc: stable@vger.kernel.org Tested-by: Devyn Liu <liudingyuan@huawei.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250410151828.2868740-6-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-11Revert "xhci: Prevent early endpoint restart when handling STALL errors."Mathias Nyman
This reverts commit 860f5d0d3594005d4588240028f42e8d2bfc725b. Paul Menzel reported that the two EP_STALLED patches in 6.15-rc1 cause regression. Turns out that the new flag may never get cleared after reset-resume, preventing xhci from restarting the endpoint. Revert this to take a proper look at it. Link: https://lore.kernel.org/linux-usb/84b400f8-2943-44e0-8803-f3aac3b670af@molgen.mpg.de cc: Paul Menzel <pmenzel@molgen.mpg.de> cc: Michal Pecio <michal.pecio@gmail.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250410151828.2868740-3-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-11Revert "xhci: Avoid queuing redundant Stop Endpoint command for stalled ↵Mathias Nyman
endpoint" This reverts commit 0c74d232578b1a7071e0312312811cb75b26b202. Paul Menzel reported that the two EP_STALLED patches in 6.15-rc1 cause regression. Turns out that the new flag may never get cleared after reset-resume, preventing xhci from restarting the endpoint. Revert this to take a proper look at it. Link: https://lore.kernel.org/linux-usb/84b400f8-2943-44e0-8803-f3aac3b670af@molgen.mpg.de cc: Paul Menzel <pmenzel@molgen.mpg.de> cc: Michal Pecio <michal.pecio@gmail.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250410151828.2868740-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-11usb: host: xhci: Notify xHCI sideband on transfer ring freeWesley Cheng
In the case of handling a USB bus reset, the xhci_discover_or_reset_device can run without first notifying the xHCI sideband client driver to stop or prevent the use of the transfer ring. It was seen that when a bus reset situation happened, the USB offload driver was attempting to fetch the xHCI transfer ring information, which was already freed. Tested-by: Puma Hsu <pumahsu@google.com> Tested-by: Daehwan Jung <dh10.jung@samsung.com> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com> Acked-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20250409194804.3773260-6-quic_wcheng@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-11usb: host: xhci-mem: Cleanup pending secondary event ring eventsWesley Cheng
As part of xHCI bus suspend, the xHCI is halted. However, if there are pending events in the secondary event ring, it is observed that the xHCI controller stops responding to further commands upon host or device initiated bus resume. Iterate through all pending events and update the dequeue pointer to the beginning of the event ring. Tested-by: Puma Hsu <pumahsu@google.com> Tested-by: Daehwan Jung <dh10.jung@samsung.com> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com> Acked-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20250409194804.3773260-3-quic_wcheng@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-05treewide: Switch/rename to timer_delete[_sync]()Thomas Gleixner
timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree over and remove the historical wrapper inlines. Conversion was done with coccinelle plus manual fixups where necessary. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-03-14usb: xhci: change xhci_resume() parameters to explicit the desired infoThéo Lebrun
Previous signature was: int xhci_resume(struct xhci_hcd *xhci, pm_message_t msg); Internally, it extracted two information out of the message: - whether we are after hibernation: msg.event == PM_EVENT_RESTORE, - whether this is an auto resume: msg.event == PM_EVENT_AUTO_RESUME. First bulletpoint is somewhat wrong: driver wants to know if the device did lose power, it doesn't care about hibernation per se. Knowing that, refactor to ask upper layers the right questions: (1) "did we lose power?" and, (2) "is this an auto resume?". Change the signature to: int xhci_resume(struct xhci_hcd *xhci, bool power_lost, bool is_auto_resume); The goal is to allow some upper layers (cdns3-plat) to tell us when power was lost after system-wise suspend. Note that lost_power is ORed at the start of xhci_resume() to xhci->quirks & XHCI_RESET_ON_RESUME || xhci->broken_suspend. It is simpler to keep those checks inside of xhci_resume() instead of doing them at each caller of xhci_resume(). Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com> Link: https://lore.kernel.org/r/20250205-s2r-cdns-v7-7-13658a271c3c@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-11xhci: Avoid queuing redundant Stop Endpoint command for stalled endpointMathias Nyman
If EP_STALLED flag is set in xhci_urb_dequeue(), without EP_HALTED or SET_DEQ_PENDING flags, then the endpoint is in stopped state and the cancelled URB can be given back immediately withouth queueing a 'stop endpoint' command. Without this change the cancelled URB would eventually be given back in the 'context state error' completion path of the 'stop endpoint' command. This is not optimal. For this improvement to work the EP_STALLED flag must be cleared with xhci lock held. Suggested-by: Michal Pecio <michal.pecio@gmail.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250311154551.4035726-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-10Merge v6.14-rc6 into usb-nextGreg Kroah-Hartman
Resolves the merge conflict with: drivers/usb/typec/ucsi/ucsi_acpi.c Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-06xhci: Prevent early endpoint restart when handling STALL errors.Mathias Nyman
Ensure that an endpoint halted due to device STALL is not restarted before a Clear_Feature(ENDPOINT_HALT) request is sent to the device. The host side of the endpoint may otherwise be started early by the 'Set TR Deq' command completion handler which is called if dequeue is moved past a cancelled or halted TD. Prevent this with a new flag set for bulk and interrupt endpoints when a Stall Error is received. Clear it in hcd->endpoint_reset() which is called after Clear_Feature(ENDPOINT_HALT) is sent. Also add a debug message if a class driver queues a new URB after the STALL. Note that class driver might not be aware of the STALL yet when it submits the URB as URBs are given back in BH. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250306144954.3507700-13-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-06xhci: show correct U1 and U2 timeout values in debug messagesMathias Nyman
U2 value is encoded in 256 microsecond intervals, show in microseconds. U1 value is in microseconds. debug message incorrectly showed "ms" Unwrap debug messages while we anyway modify them. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250306144954.3507700-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-04usb: xhci: Fix host controllers "dying" after suspend and resumeMichal Pecio
A recent cleanup went a bit too far and dropped clearing the cycle bit of link TRBs, so it stays different from the rest of the ring half of the time. Then a race occurs: if the xHC reaches such link TRB before more commands are queued, the link's cycle bit unintentionally matches the xHC's cycle so it follows the link and waits for further commands. If more commands are queued before the xHC gets there, inc_enq() flips the bit so the xHC later sees a mismatch and stops executing commands. This function is called before suspend and 50% of times after resuming the xHC is doomed to get stuck sooner or later. Then some Stop Endpoint command fails to complete in 5 seconds and this shows up xhci_hcd 0000:00:10.0: xHCI host not responding to stop endpoint command xhci_hcd 0000:00:10.0: xHCI host controller not responding, assume dead xhci_hcd 0000:00:10.0: HC died; cleaning up followed by loss of all USB decives on the affected bus. That's if you are lucky, because if Set Deq gets stuck instead, the failure is silent. Likely responsible for kernel bug 219824. I found this while searching for possible causes of that regression and reproduced it locally before hearing back from the reporter. To repro, simply wait for link cycle to become set (debugfs), then suspend, resume and wait. To accelerate the failure I used a script which repeatedly starts and stops a UVC camera. Some HCs get fully reinitialized on resume and they are not affected. Link: https://bugzilla.kernel.org/show_bug.cgi?id=219824 Fixes: 36b972d4b7ce ("usb: xhci: improve xhci_clear_command_ring()") Cc: stable@vger.kernel.org Signed-off-by: Michal Pecio <michal.pecio@gmail.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20250304113147.3322584-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-15USB: host: Use str_enable_disable-like helpersKrzysztof Kozlowski
Replace ternary (condition ? "enable" : "disable") syntax with helpers from string_choices.h because: 1. Simple function call with one argument is easier to read. Ternary operator has three arguments and with wrapping might lead to quite long code. 2. Is slightly shorter thus also easier to read. 3. It brings uniformity in the text - same string. 4. Allows deduping by the linker, which results in a smaller binary file. Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Link: https://lore.kernel.org/r/20250114-str-enable-disable-usb-v1-2-c8405df47c19@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-06usb: xhci: Avoid queuing redundant Stop Endpoint commandsMichal Pecio
Stop Endpoint command on an already stopped endpoint fails and may be misinterpreted as a known hardware bug by the completion handler. This results in an unnecessary delay with repeated retries of the command. Avoid queuing this command when endpoint state flags indicate that it's stopped or halted and the command will fail. If commands are pending on the endpoint, their completion handlers will process cancelled TDs so it's done. In case of waiting for external operations like clearing TT buffer, the endpoint is stopped and cancelled TDs can be processed now. This eliminates practically all unnecessary retries because an endpoint with pending URBs is maintained in Running state by the driver, unless aforementioned commands or other operations are pending on it. This is guaranteed by xhci_ring_ep_doorbell() and by the fact that it is called every time any of those operations completes. The only known exceptions are hardware bugs (the endpoint never starts at all) and Stream Protocol errors not associated with any TRB, which cause an endpoint reset not followed by restart. Sounds like a bug. Generally, these retries are only expected to happen when the endpoint fails to start for unknown/no reason, which is a worse problem itself, and fixing the bug eliminates the retries too. All cases were tested and found to work as expected. SET_DEQ_PENDING was produced by patching uvcvideo to unlink URBs in 100us intervals, which then runs into this case very often. EP_HALTED was produced by restarting 'cat /dev/ttyUSB0' on a serial dongle with broken cable. EP_CLEARING_TT by the same, with the dongle on an external hub. Fixes: fd9d55d190c0 ("xhci: retry Stop Endpoint on buggy NEC controllers") CC: stable@vger.kernel.org Signed-off-by: Michal Pecio <michal.pecio@gmail.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20241106101459.775897-34-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-06usb: xhci: Limit Stop Endpoint retriesMichal Pecio
Some host controllers fail to atomically transition an endpoint to the Running state on a doorbell ring and enter a hidden "Restarting" state, which looks very much like Stopped, with the important difference that it will spontaneously transition to Running anytime soon. A Stop Endpoint command queued in the Restarting state typically fails with Context State Error and the completion handler sees the Endpoint Context State as either still Stopped or already Running. Even a case of Halted was observed, when an error occurred right after the restart. The Halted state is already recovered from by resetting the endpoint. The Running state is handled by retrying Stop Endpoint. The Stopped state was recognized as a problem on NEC controllers and worked around also by retrying, because the endpoint soon restarts and then stops for good. But there is a risk: the command may fail if the endpoint is "stopped for good" already, and retries will fail forever. The possibility of this was not realized at the time, but a number of cases were discovered later and reproduced. Some proved difficult to deal with, and it is outright impossible to predict if an endpoint may fail to ever start at all due to a hardware bug. One such bug (albeit on ASM3142, not on NEC) was found to be reliably triggered simply by toggling an AX88179 NIC up/down in a tight loop for a few seconds. An endless retries storm is quite nasty. Besides putting needless load on the xHC and CPU, it causes URBs never to be given back, paralyzing the device and connection/disconnection logic for the whole bus if the device is unplugged. User processes waiting for URBs become unkillable, drivers and kworker threads lock up and xhci_hcd cannot be reloaded. For peace of mind, impose a timeout on Stop Endpoint retries in this case. If they don't succeed in 100ms, consider the endpoint stopped permanently for some reason and just give back the unlinked URBs. This failure case is rare already and work is under way to make it rarer. Start this work today by also handling one simple case of race with Reset Endpoint, because it costs just two lines to implement. Fixes: fd9d55d190c0 ("xhci: retry Stop Endpoint on buggy NEC controllers") CC: stable@vger.kernel.org Signed-off-by: Michal Pecio <michal.pecio@gmail.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20241106101459.775897-32-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-06usb: xhci: improve xhci_clear_command_ring()Niklas Neronin
Remove redundant TRB cycle reset, the TRB cycle is already set to zero by the preceding memset(), making the explicit reset unnecessary. Clarify ring loop start point. Change the loop start from the dequeue segment to the start segment. Both approaches achieve the same result, but starting from the start segment makes it clearer that the entire ring is being zeroed out. Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20241106101459.775897-27-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-06usb: xhci: move link TRB quirk to xhci_gen_setup()Niklas Neronin
This quirk is old and seldom seen, as a result the trace is changed to debug message and only printed when the quirk is set. Move it into xhci_gen_setup() where the majority of quirks are set. Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20241106101459.775897-25-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-06usb: xhci: simplify TDs start and end naming scheme in struct 'xhci_td'Niklas Neronin
Old names: * start_seg - last_trb_seg * first_trb - last_trb New names: * start_seg - end_seg * start_trb - end_trb A Transfer Descriptor (TD) in the xhci driver is a data structure that represents a single transaction to be performed by the USB host controller. This transaction is defined by TRBs from 'start_trb' in 'start_seg' to 'end_trb' in 'end_seg'. The terms "start" and "end" were chosen over "first" and "last" for ease of searching within the codebase. The ring structure uses 'first_seg' and 'last_seg', while the TD structure uses 'start_seg' and 'end_seg'. Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20241106101459.775897-24-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-06xhci: Don't issue Reset Device command to Etron xHCI hostKuangyi Chiang
Sometimes the hub driver does not recognize the USB device connected to the external USB2.0 hub when the system resumes from S4. After the SetPortFeature(PORT_RESET) request is completed, the hub driver calls the HCD reset_device callback, which will issue a Reset Device command and free all structures associated with endpoints that were disabled. This happens when the xHCI driver issue a Reset Device command to inform the Etron xHCI host that the USB device associated with a device slot has been reset. Seems that the Etron xHCI host can not perform this command correctly, affecting the USB device. To work around this, the xHCI driver should obtain a new device slot with reference to commit 651aaf36a7d7 ("usb: xhci: Handle USB transaction error on address command"), which is another way to inform the Etron xHCI host that the USB device has been reset. Add a new XHCI_ETRON_HOST quirk flag to invoke the workaround in xhci_discover_or_reset_device(). Fixes: 2a8f82c4ceaf ("USB: xhci: Notify the xHC when a device is reset.") Cc: stable@vger.kernel.org Signed-off-by: Kuangyi Chiang <ki.chiang65@gmail.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20241106101459.775897-19-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-06usb: xhci: remove option to change a default ring's TRB cycle bitNiklas Neronin
The TRB cycle bit indicates TRB ownership by the Host Controller (HC) or Host Controller Driver (HCD). New rings are initialized with 'cycle_state' equal to one, and all its TRBs' cycle bits are set to zero. When handling ring expansion, set the source ring cycle bits to the same value as the destination ring. Move the cycle bit setting from xhci_segment_alloc() to xhci_link_rings(), and remove the 'cycle_state' argument from xhci_initialize_ring_info(). The xhci_segment_alloc() function uses kzalloc_node() to allocate segments, ensuring that all TRB cycle bits are initialized to zero. Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20241106101459.775897-12-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-06usb: xhci: introduce macro for ring segment list iterationNiklas Neronin
Add macro to streamline and standardize the iteration over ring segment list. xhci_for_each_ring_seg(): Iterates over the entire ring segment list. The xhci_free_segments_for_ring() function's while loop has not been updated to use the new macro. This function has some underlying issues, and as a result, it will be handled separately in a future patch. Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20241106101459.775897-11-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-17xhci: add helper to stop endpoint and wait for completionMathias Nyman
Expose xhci_stop_endpoint_sync() which is a synchronous variant of xhci_queue_stop_endpoint(). This is useful for client drivers that are using the secondary interrupters, and need to stop the current endpoint session. This does not go through the normal xhci_handle_cmd_stop_ep() command completion handler, because it utilizes the completion path to achieve synchronous behavior. Users of this API are primarily intended to be clients that maintain their own transfer rings, such as in the case of USB audio offload. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com> Link: https://lore.kernel.org/r/20241015212915.1206789-3-quic_wcheng@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>