kernel/drivers/pinctrl/intel/pinctrl-baytrail.c, branch linux-4.3.y

genirq: Remove irq argument from irq flow handlers

2015-09-16T13:47:51Z

Most interrupt flow handlers do not use the irq argument. Those few which use it can retrieve the irq number from the irq descriptor. Remove the argument. Search and replace was done with coccinelle and some extra helper scripts around it. Thanks to Julia for her help! Signed-off-by: Thomas Gleixner Cc: Julia Lawall Cc: Jiang Liu

pinctrl: baytrail: Use raw_spinlock for locking

2015-08-26T07:25:33Z

The Intel Baytrail pinctrl driver implements irqchip callbacks which are called with desc->lock raw_spinlock held. In mainline this is fine because spinlock resolves to raw_spinlock. However, running the same code in -rt we get: BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:917 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/0 Preemption disabled at:[] cpu_startup_entry+0x17f/0x480 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.1.5-rt5 #13 ... Call Trace: [] dump_stack+0x4a/0x61 [] ___might_sleep+0xe7/0x170 [] rt_spin_lock+0x1f/0x50 [] byt_gpio_clear_triggering+0x38/0x60 [] byt_irq_mask+0x11/0x20 [] handle_level_irq+0x83/0x150 [] generic_handle_irq+0x27/0x40 [] byt_gpio_irq_handler+0x7f/0xc0 [] handle_irq+0xaa/0x190 ... This is because in -rt spinlocks are preemptible so taking the driver private spinlock in irqchip callbacks causes might_sleep() to trigger. In order to keep -rt happy but at the same time make sure that register accesses get serialized, convert the driver to use raw_spinlock instead. Also shorten the critical section a bit in few places. Suggested-by: Linus Walleij Signed-off-by: Mika Westerberg Signed-off-by: Linus Walleij

pinctrl: baytrail: Serialize all register access

2015-08-13T12:26:14Z

There is a hardware issue in Intel Baytrail where concurrent GPIO register access might result reads of 0xffffffff and writes might get dropped completely. Prevent this from happening by taking the serializing lock in all places where it is possible that more than one thread might be accessing the hardware concurrently. Signed-off-by: Mika Westerberg Signed-off-by: Linus Walleij

pinctrl: baytrail: Drop FSF mailing address

2015-08-13T12:25:29Z

The FSF address is already mentioned in the COPYING file. No need to duplicate that information to individual files. Signed-off-by: Mika Westerberg Signed-off-by: Linus Walleij

pinctrl/baytrail: Use irq_set_handler_locked()

2015-07-17T19:56:16Z

Use irq_set_handler_locked() as it avoids a redundant lookup of the irq descriptor. Search and replacement was done with coccinelle. Signed-off-by: Thomas Gleixner Cc: Jiang Liu Cc: Julia Lawall Cc: Linus Walleij Cc: linux-gpio@vger.kernel.org

pinctrl: baytrail: Save pin context over system sleep

2015-03-06T11:25:07Z

The BIOS might reconfigure pins as it needs when S3 is entered. This might cause drivers using the GPIOs to fail because the state was wrong or interrupts stopped working. Fix this by saving and restoring enough pin context over system sleep. Reported-by: Hans Holmberg Signed-off-by: Mika Westerberg Signed-off-by: Linus Walleij

pinctrl: baytrail: Rework interrupt handling

2015-03-06T11:22:41Z

Instead of handling everything in the driver's first level interrupt handler, we can take advantage of already existing flow handlers that are provided by the IRQ core. This changes the functionality a bit also. Previously the driver looped over pending interrupts in a single loop, restarting the loop if some interrupt changed state. This caused problem with Lenovo Thinkpad 10 digitizer that it was not able to deassert the interrupt before the driver disabled the interrupt for good (looplimit was exhausted). Rework the interrupt handling logic a bit so that we provide proper mask, ack and unmask operations in terms of Baytrail GPIO hardware and loop over pending interrupts only once. If the interrupt remains asserted the first level handler will be re-triggered automatically. Signed-off-by: Mika Westerberg Signed-off-by: Linus Walleij

pinctrl: baytrail: Clear interrupt triggering from pins that are in GPIO mode

2015-03-06T11:21:09Z

If the pin is already configured as GPIO and it has any of the triggering flags set, we may get spurious interrupts depending on the state of the pin. Prevent this by clearing the triggering flags on such pins. However, if the pin is also configured as "direct IRQ" we leave the flags as is. Otherwise it will prevent interrupts that are routed directly to IO-APIC. Signed-off-by: Mika Westerberg Signed-off-by: Linus Walleij

pinctrl: baytrail: Relax GPIO request rules

2015-03-06T11:19:51Z

Zotac ZBOX PI320, a Baytrail based mini-PC, has power button connected to a GPIO pin and it is exposed to the operating system as Windows 8 button array. This is implemented in Linux as a driver using gpio_keys. However, BIOS on this particula machine forgot to mux the pin to be a GPIO instead of native function, which results following message to be seen on the console: byt_gpio INT33FC:02: pin 16 cannot be used as GPIO. This causes power button to not work as the driver was not able to request the GPIO it needs. So instead of completely preventing this we allow turning the pin as GPIO but issue warning that something might be wrong. Reported-by: Benjamin Adler Signed-off-by: Mika Westerberg Signed-off-by: Linus Walleij

Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2014-12-15T00:10:09Z

Pull driver core update from Greg KH: "Here's the set of driver core patches for 3.19-rc1. They are dominated by the removal of the .owner field in platform drivers. They touch a lot of files, but they are "simple" changes, just removing a line in a structure. Other than that, a few minor driver core and debugfs changes. There are some ath9k patches coming in through this tree that have been acked by the wireless maintainers as they relied on the debugfs changes. Everything has been in linux-next for a while" * tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits) Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries" fs: debugfs: add forward declaration for struct device type firmware class: Deletion of an unnecessary check before the function call "vunmap" firmware loader: fix hung task warning dump devcoredump: provide a one-way disable function device: Add dev__once variants ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries ath: use seq_file api for ath9k debugfs files debugfs: add helper function to create device related seq_file drivers/base: cacheinfo: remove noisy error boot message Revert "core: platform: add warning if driver has no owner" drivers: base: support cpu cache information interface to userspace via sysfs drivers: base: add cpu_device_create to support per-cpu devices topology: replace custom attribute macros with standard DEVICE_ATTR* cpumask: factor out show_cpumap into separate helper function driver core: Fix unbalanced device reference in drivers_probe driver core: fix race with userland in device_add() sysfs/kernfs: make read requests on pre-alloc files use the buffer. sysfs/kernfs: allow attributes to request write buffer be pre-allocated. fs: sysfs: return EGBIG on write if offset is larger than file size ...