kernel/drivers/tty/serial/8250, branch linux-rolling-stable

serial: 8250: 8250_omap.c: Clear DMA RX running status only after DMA termination is done

2026-03-04T12:20:42Z

[ Upstream commit a5fd8945a478ff9be14812693891d7c9b4185a50 ] Clear rx_running flag only after DMA teardown polling completes. In the previous implementation the flag was being cleared while hardware teardown was still in progress, creating a mismatch between software state (flag = 0, "ready") and hardware state (still terminating). Signed-off-by: Moteen Shah Link: https://patch.msgid.link/20260112081829.63049-3-m-shah@ti.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: 8250: 8250_omap.c: Add support for handling UART error conditions

2026-03-04T12:20:41Z

[ Upstream commit 623b07b370e9963122d167e04fdc1dc713ebfbaf ] The DMA IRQ handler does not accounts for the overrun(OE) or any other errors being reported by the IP before triggering a DMA transaction which leads to the interrupts not being handled resulting into an IRQ storm. The way to handle OE is to: 1. Reset the RX FIFO. 2. Read the UART_RESUME register, which clears the internal flag Earlier, the driver issued DMA transations even in case of OE which shouldn't be done according to the OE handling mechanism mentioned above, as we are resetting the FIFO's, refer section: "12.1.6.4.8.1.3.6 Overrun During Receive" [0]. [0] https://www.ti.com/lit/pdf/spruiu1 Signed-off-by: Moteen Shah Link: https://patch.msgid.link/20260112081829.63049-2-m-shah@ti.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: 8250_dw: handle clock enable errors in runtime_resume

2026-03-04T12:20:38Z

[ Upstream commit d31228143a489ba6ba797896a07541ce06828c09 ] Add error checking for clk_prepare_enable() calls in dw8250_runtime_resume(). Currently if either clock fails to enable, the function returns success while leaving clocks in inconsistent state. This change implements comprehensive error handling by checking the return values of both clk_prepare_enable() calls. If the second clock enable operation fails after the first clock has already been successfully enabled, the code now properly cleans up by disabling and unpreparing the first clock before returning. The error code is then propagated to the caller, ensuring that clock enable failures are properly reported rather than being silently ignored. Signed-off-by: Artem Shimko Link: https://patch.msgid.link/20251104145433.2316165-2-a.shimko.dev@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: 8250_pci: Fix broken RS485 for F81504/508/512

2026-01-16T13:29:10Z

Fintek F81504/508/512 can support both RTS_ON_SEND and RTS_AFTER_SEND, but pci_fintek_rs485_supported only announces the former. This makes it impossible to unset SER_RS485_RTS_ON_SEND from userspace because of uart_sanitize_serial_rs485(). Some devices with these chips need RTS low on TX, so they are effectively broken. Fix this by announcing the support for SER_RS485_RTS_AFTER_SEND, similar to commit 068d35a7be65 ("serial: sc16is7xx: announce support for SER_RS485_RTS_ON_SEND"). Fixes: 4afeced55baa ("serial: core: fix sanitizing check for RTS settings") Cc: stable Signed-off-by: Marnix Rijnart Link: https://patch.msgid.link/20260112000931.61703-1-marnix.rijnart@iwell.eu Signed-off-by: Greg Kroah-Hartman

serial: 8250: longson: Fix NULL vs IS_ERR() bug in probe

2025-12-17T14:11:00Z

The devm_platform_get_and_ioremap_resource() function never returns NULL, it returns error pointers. Fix the error checking to match. Fixes: 25e95d763176 ("serial: 8250: Add Loongson uart driver support") Signed-off-by: Dan Carpenter Link: https://patch.msgid.link/aSsIa3KdAlXh5uQC@stanley.mountain Signed-off-by: Greg Kroah-Hartman

Merge tag 'tty-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2025-12-07T02:38:19Z

Pull tty/serial updates from Greg KH: "Here is the big set of tty/serial driver changes for 6.19-rc1. Nothing major at all, just small constant churn to make the tty layer "cleaner" as well as serial driver updates and even a new test added! Included in here are: - More tty/serial cleanups from Jiri - tty tiocsti test added to hopefully ensure we don't regress in this area again - sc16is7xx driver updates - imx serial driver updates - 8250 driver updates - new hardware device ids added - other minor serial/tty driver cleanups and tweaks All of these have been in linux-next for a while with no reported issues" * tag 'tty-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (60 commits) serial: sh-sci: Fix deadlock during RSCI FIFO overrun error dt-bindings: serial: rsci: Drop "uart-has-rtscts: false" LoongArch: dts: Add uart new compatible string serial: 8250: Add Loongson uart driver support dt-bindings: serial: 8250: Add Loongson uart compatible serial: 8250: add driver for KEBA UART serial: Keep rs485 settings for devices without firmware node serial: qcom-geni: Enable Serial on SA8255p Qualcomm platforms serial: qcom-geni: Enable PM runtime for serial driver serial: sprd: Return -EPROBE_DEFER when uart clock is not ready tty: serial: samsung: Declare earlycon for Exynos850 serial: icom: Convert PCIBIOS_* return codes to errnos serial: 8250-of: Fix style issues in 8250_of.c serial: add support of CPCI cards serial: mux: Fix kernel doc for mux_poll() tty: replace use of system_unbound_wq with system_dfl_wq serial: 8250_platform: simplify IRQF_SHARED handling serial: 8250: make share_irqs local to 8250_platform serial: 8250: move skip_txen_test to core serial: drop SERIAL_8250_DEPRECATED_OPTIONS ...

Merge tag 'pci-v6.19-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci

2025-12-05T01:29:41Z

Pull PCI updates from Bjorn Helgaas: "Enumeration: - Enable host bridge emulation for PCI_DOMAINS_GENERIC platforms (Dan Williams) - Switch vmd from custom domain number allocator to the common allocator to prevent a potential race with new non-VMD buses (Dan Williams) - Enable Precision Time Measurement (PTM) only if device advertises support for a relevant role, to prevent invalid PTM Requests that cause ACS violations that are reported as AER Uncorrectable Non-Fatal errors (Mika Westerberg) Resource management: - Prevent resource tree corruption when BAR resize fails (Ilpo Järvinen) - Restore BARs to the original size if a BAR resize fails (Ilpo Järvinen) - Remove BAR release from BAR resize attempts by the xe, i915, and amdgpu drivers so the PCI core can restore BARs if the resize fails (Ilpo Järvinen) - Move Resizable BAR code to rebar.c (Ilpo Järvinen) - Add pci_rebar_size_supported() and use it in i915 and xe (Ilpo Järvinen) - Add pci_rebar_get_max_size() and use it in xe and amdgpu (Ilpo Järvinen) Power management and error handling: - For drivers using PCI legacy suspend, save config state at suspend so that state (not any earlier state from enumeration, probe, or error recovery) will be restored when resuming (Lukas Wunner) - For devices with no driver or a driver that lacks power management, save config state at hibernate so that state (not any earlier state from enumeration, probe, or error recovery) will be restored when resuming (Lukas Wunner) - Save device config space on device addition, before driver binding, so error recovery works more reliably (Lukas Wunner) - Drop pci_save_state() from several drivers that no longer need it since the PCI core always does it and pci_restore_state() no longer invalidates the saved state (Lukas Wunner) - Document use of pci_save_state() by drivers to capture the state they want restored during error recovery (Lukas Wunner) Power control: - Add a struct pci_ops.assert_perst() function pointer to assert/deassert PCIe PERST# and implement it for the qcom driver (Krishna Chaitanya Chundru) - Add DT binding and pwrctrl driver for the Toshiba TC9563 PCIe switch, which must be held in reset after poweron so the pwrctrl driver can configure the switch via I2C before bringing up the links (Krishna Chaitanya Chundru) Endpoint framework: - Convert the endpoint doorbell test to use a threaded IRQ to fix a 'sleeping while atomic' issue (Bhanu Seshu Kumar Valluri) - Add endpoint VNTB MSI doorbell support to reduce latency between host and endpoint (Frank Li) New native PCIe controller drivers: - Add CIX Sky1 host controller DT binding and driver (Hans Zhang) - Add NXP S32G host controller DT binding and driver (Vincent Guittot) - Add Renesas RZ/G3S host controller DT binding and driver (Claudiu Beznea) - Add SpacemiT K1 host controller DT binding and driver (Alex Elder) Amlogic Meson PCIe controller driver: - Update DT binding to name DBI region 'dbi', not 'elbi', and update driver to support both (Manivannan Sadhasivam) Apple PCIe controller driver: - Move struct pci_host_bridge allocation from pci_host_common_init() to callers, which significantly simplifies pcie-apple (Marc Zyngier) Broadcom STB PCIe controller driver: - Disable advertising ASPM L0s support correctly (Jim Quinlan) - Add a panic/die handler to print diagnostic info in case PCIe caused an unrecoverable abort (Jim Quinlan) Cadence PCIe controller driver: - Add module support for Cadence platform host and endpoint controller driver (Manikandan K Pillai) - Split headers into 'legacy' (LGA) and 'high perf' (HPA) to prepare for new CIX Sky1 driver (Manikandan K Pillai) MediaTek PCIe controller driver: - Convert DT binding to YAML schema (Christian Marangi) - Add Airoha AN7583 DT compatible and driver support (Christian Marangi) Qualcomm PCIe controller driver: - Add Qualcomm Kaanapali to SM8550 DT binding (Qiang Yu) - Add required 'power-domains' and 'resets' to qcom sa8775p, sc7280, sc8280xp, sm8150, sm8250, sm8350, sm8450, sm8550, x1e80100 DT schemas (Krzysztof Kozlowski) - Look up OPP using both frequency and data rate (not just frequency) so RPMh votes can account for both (Krishna Chaitanya Chundru) Rockchip DesignWare PCIe controller driver: - Add Rockchip RK3528 compatible strings in DT binding (Yao Zi) STMicroelectronics STM32MP25 PCIe controller driver: - Fix a race between link training and endpoint register initialization (Christian Bruel) - Align endpoint allocations to match the ATU requirements (Christian Bruel) Synopsys DesignWare PCIe controller driver: - Clear L1 PM Substate Capability 'Supported' bits unless glue driver says it's supported, which prevents users from enabling non-working L1SS. Currently only qcom and tegra194 support L1SS (Bjorn Helgaas) - Remove now-superfluous L1SS disable code from tegra194 (Bjorn Helgaas) - Configure L1SS support in dw-rockchip when DT says 'supports-clkreq' (Shawn Lin) TI Keystone PCIe controller driver: - Fail the probe instead of silently succeeding if ks_pcie_of_data didn't specify Root Complex or Endpoint mode (Siddharth Vadapalli) - Make keystone buildable as a loadable module, except on ARM32 where hook_fault_code() is __init (Siddharth Vadapalli)" * tag 'pci-v6.19-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (100 commits) MAINTAINERS: Add Manivannan Sadhasivam as PCI/pwrctrl maintainer MAINTAINERS: Add CIX Sky1 PCIe controller driver maintainer PCI: sky1: Add PCIe host support for CIX Sky1 dt-bindings: PCI: Add CIX Sky1 PCIe Root Complex bindings PCI: cadence: Add support for High Perf Architecture (HPA) controller MAINTAINERS: Add NXP S32G PCIe controller driver maintainer PCI: s32g: Add NXP S32G PCIe controller driver (RC) PCI: dwc: Add register and bitfield definitions dt-bindings: PCI: s32g: Add NXP S32G PCIe controller PCI: Add Renesas RZ/G3S host controller driver PCI: host-generic: Move bridge allocation outside of pci_host_common_init() dt-bindings: PCI: Add Renesas RZ/G3S PCIe controller binding PCI: Validate pci_rebar_size_supported() input Documentation: PCI: Amend error recovery doc with pci_save_state() rules treewide: Drop pci_save_state() after pci_restore_state() PCI/ERR: Ensure error recoverability at all times PCI/PM: Stop needlessly clearing state_saved on enumeration and thaw PCI/PM: Reinstate clearing state_saved in legacy and !PM codepaths PCI: dw-rockchip: Configure L1SS support PCI: tegra194: Remove unnecessary L1SS disable code ...

serial: 8250: Fix 8250_rsa symbol loop

2025-11-26T12:16:53Z

Depmod fails for a kernel made with: make allnoconfig echo -e "CONFIG_MODULES=y\nCONFIG_SERIAL_8250=m\nCONFIG_SERIAL_8250_EXTENDED=y\nCONFIG_SERIAL_8250_RSA=y" >> .config make olddefconfig ...due to a dependency loop: depmod: ERROR: Cycle detected: 8250 -> 8250_base -> 8250 depmod: ERROR: Found 2 modules in dependency cycles! This is caused by the move of 8250 RSA code from 8250_port.c (in 8250_base.ko) into 8250_rsa.c (in 8250.ko) by the commit 5a128fb475fb ("serial: 8250: move RSA functions to 8250_rsa.c"). The commit b20d6576cdb3 ("serial: 8250: export RSA functions") tried to fix a missing symbol issue with EXPORTs but those then cause this dependency cycle. Break dependency loop by moving 8250_rsa.o from 8250.ko to 8250_base.ko and by passing univ8250_port_base_ops to univ8250_rsa_support() that can make a local copy of it. Reported-by: Stephen Rothwell Reported-by: Alex Davis Fixes: 5a128fb475fb ("serial: 8250: move RSA functions to 8250_rsa.c") Fixes: b20d6576cdb3 ("serial: 8250: export RSA functions") Cc: stable Link: https://lore.kernel.org/all/87frc3sd8d.fsf@posteo.net/ Link: https://lore.kernel.org/all/CADiockCvM6v+d+UoFZpJSMoLAdpy99_h-hJdzUsdfaWGn3W7-g@mail.gmail.com/ Reviewed-by: Andy Shevchenko Reviewed-by: Jiri Slaby Signed-off-by: Ilpo Järvinen Link: https://patch.msgid.link/20251110105043.4062-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: 8250: Add Loongson uart driver support

2025-11-26T12:15:17Z

Add the driver for on-chip UART used on Loongson family chips. The hardware is similar to NS16550A, but there are the following differences: - Some chips (such as Loongson-2K2000) have added a fractional division register to obtain the required baud rate accurately, so the {get,set}_divisor callback is overridden. - Due to hardware defects, quirk handling is required for UART_MCR/UART_MSR. Co-developed-by: Haowei Zheng Signed-off-by: Haowei Zheng Signed-off-by: Binbin Zhou Reviewed-by: Huacai Chen Link: https://patch.msgid.link/2c2a01a276b9250efea0c7aa190efecdfd6fdf5a.1760166651.git.zhoubinbin@loongson.cn Signed-off-by: Greg Kroah-Hartman

serial: 8250: add driver for KEBA UART

2025-11-26T12:13:37Z

The KEBA UART is found in the system FPGA of KEBA PLC devices. It is mostly 8250 compatible with extension for some UART modes. 3 different variants exist. The simpliest variant supports only RS-232 and is used for debug interfaces. The next variant supports only RS-485 and is used mostly for communication with KEBA panel devices. The third variant is able to support RS-232, RS-485 and RS-422. For this variant not only the mode of the UART is configured, also the physics and transceivers are switched according to the mode. Signed-off-by: Gerhard Engleder Tested-by: Daniel Gierlinger Reviewed-by: Lukas Wunner Link: https://patch.msgid.link/20251023151229.11774-3-gerhard@engleder-embedded.com Signed-off-by: Greg Kroah-Hartman