linux/drivers/gpio/gpio-grgpio.c, branch v6.0

gpio: grgpio: Fix device removing

2022-06-23T14:42:27Z

If a platform device's remove callback returns non-zero, the device core emits a warning and still removes the device and calls the devm cleanup callbacks. So it's not save to not unregister the gpiochip because on the next request to a GPIO the driver accesses kfree()'d memory. Also if an IRQ triggers, the freed memory is accessed. Instead rely on the GPIO framework to ensure that after gpiochip_remove() all GPIOs are freed and so the corresponding IRQs are unmapped. This is a preparation for making platform remove callbacks return void. Signed-off-by: Uwe Kleine-König Reviewed-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski

gpio: use raw spinlock for gpio chip shadowed data

2022-04-25T10:10:02Z

In case of PREEMPT_RT, there is a raw_spinlock -> spinlock dependency as the lockdep report shows. __irq_set_handler irq_get_desc_buslock __irq_get_desc_lock raw_spin_lock_irqsave(&desc->lock, *flags); // raw spinlock get here __irq_do_set_handler mask_ack_irq dwapb_irq_ack spin_lock_irqsave(&gc->bgpio_lock, flags); // sleep able spinlock irq_put_desc_busunlock Replace with a raw lock to avoid BUGs. This lock is only used to access registers, and It's safe to replace with the raw lock without bad influence. [ 15.090359][ T1] ============================= [ 15.090365][ T1] [ BUG: Invalid wait context ] [ 15.090373][ T1] 5.10.59-rt52-00983-g186a6841c682-dirty #3 Not tainted [ 15.090386][ T1] ----------------------------- [ 15.090392][ T1] swapper/0/1 is trying to lock: [ 15.090402][ T1] 70ff00018507c188 (&gc->bgpio_lock){....}-{3:3}, at: _raw_spin_lock_irqsave+0x1c/0x28 [ 15.090470][ T1] other info that might help us debug this: [ 15.090477][ T1] context-{5:5} [ 15.090485][ T1] 3 locks held by swapper/0/1: [ 15.090497][ T1] #0: c2ff0001816de1a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock+0x98/0x104 [ 15.090553][ T1] #1: ffff90001485b4b8 (irq_domain_mutex){+.+.}-{4:4}, at: irq_domain_associate+0xbc/0x6d4 [ 15.090606][ T1] #2: 4bff000185d7a8e0 (lock_class){....}-{2:2}, at: _raw_spin_lock_irqsave+0x1c/0x28 [ 15.090654][ T1] stack backtrace: [ 15.090661][ T1] CPU: 4 PID: 1 Comm: swapper/0 Not tainted 5.10.59-rt52-00983-g186a6841c682-dirty #3 [ 15.090682][ T1] Hardware name: Horizon Robotics Journey 5 DVB (DT) [ 15.090692][ T1] Call trace: ...... [ 15.090811][ T1] _raw_spin_lock_irqsave+0x1c/0x28 [ 15.090828][ T1] dwapb_irq_ack+0xb4/0x300 [ 15.090846][ T1] __irq_do_set_handler+0x494/0xb2c [ 15.090864][ T1] __irq_set_handler+0x74/0x114 [ 15.090881][ T1] irq_set_chip_and_handler_name+0x44/0x58 [ 15.090900][ T1] gpiochip_irq_map+0x210/0x644 Signed-off-by: Schspa Shi Reviewed-by: Andy Shevchenko Acked-by: Linus Walleij Acked-by: Doug Berger Acked-by: Serge Semin Signed-off-by: Bartosz Golaszewski

gpio: Get rid of duplicate of_node assignment in the drivers

2021-12-17T16:39:35Z

GPIO library does copy the of_node from the parent device of the GPIO chip, there is no need to repeat this in the individual drivers. Remove these assignment all at once. For the details one may look into the of_gpio_dev_init() implementation. While at it, remove duplicate parent device assignment where it is the case. Signed-off-by: Andy Shevchenko Reviewed-By: Matti Vaittinen Signed-off-by: Bartosz Golaszewski

gpio: Remove the unused flags

2020-01-15T10:24:19Z

drivers/gpio/gpio-grgpio.c: In function ‘grgpio_remove’: drivers/gpio/gpio-grgpio.c:438:16: warning: unused variable ‘flags’ [-Wunused-variable] unsigned long flags; ^ Fixes: 25d071b3f6db ("gpio: gpio-grgpio: fix possible sleep-in-atomic-context bugs in grgpio_remove()") Signed-off-by: Shaokun Zhang Link: https://lore.kernel.org/r/1579009062-7154-1-git-send-email-zhangshaokun@hisilicon.com Reviewed-by: Bartosz Golaszewski Signed-off-by: Linus Walleij

gpio: gpio-grgpio: fix possible sleep-in-atomic-context bugs in grgpio_irq_map/unmap()

2020-01-07T12:37:11Z

The driver may sleep while holding a spinlock. The function call path (from bottom to top) in Linux 4.19 is: drivers/gpio/gpio-grgpio.c, 261: request_irq in grgpio_irq_map drivers/gpio/gpio-grgpio.c, 255: _raw_spin_lock_irqsave in grgpio_irq_map drivers/gpio/gpio-grgpio.c, 318: free_irq in grgpio_irq_unmap drivers/gpio/gpio-grgpio.c, 299: _raw_spin_lock_irqsave in grgpio_irq_unmap request_irq() and free_irq() can sleep at runtime. To fix these bugs, request_irq() and free_irq() are called without holding the spinlock. These bugs are found by a static analysis tool STCheck written by myself. Signed-off-by: Jia-Ju Bai Link: https://lore.kernel.org/r/20191218132605.10594-1-baijiaju1990@gmail.com Signed-off-by: Linus Walleij

gpio: gpio-grgpio: fix possible sleep-in-atomic-context bugs in grgpio_remove()

2020-01-07T12:37:10Z

drivers/gpio/gpiolib-sysfs.c, 796: mutex_lock in gpiochip_sysfs_unregister drivers/gpio/gpiolib.c, 1455: gpiochip_sysfs_unregister in gpiochip_remove drivers/gpio/gpio-grgpio.c, 460: gpiochip_remove in grgpio_remove drivers/gpio/gpio-grgpio.c, 449: _raw_spin_lock_irqsave in grgpio_remove kernel/irq/irqdomain.c, 243: mutex_lock in irq_domain_remove drivers/gpio/gpio-grgpio.c, 463: irq_domain_remove in grgpio_remove drivers/gpio/gpio-grgpio.c, 449: _raw_spin_lock_irqsave in grgpio_remove mutex_lock() can sleep at runtime. To fix these bugs, the lock is dropped in grgpio_remove(), because there is no need for locking in remove() callbacks. These bugs are found by a static analysis tool STCheck written by myself. Signed-off-by: Jia-Ju Bai Link: https://lore.kernel.org/r/20191219131459.18640-1-baijiaju1990@gmail.com Signed-off-by: Linus Walleij

gpio: Remove dev_err() usage after platform_get_irq()

2019-08-05T11:25:34Z

We don't need dev_err() messages when platform_get_irq() fails now that platform_get_irq() prints an error message itself when something goes wrong. Let's remove these prints with a simple semantic patch. // @@ expression ret; struct platform_device *E; @@ ret = ( platform_get_irq(E, ...) | platform_get_irq_byname(E, ...) ); if ( \( ret < 0 \| ret <= 0 \) ) { ( -if (ret != -EPROBE_DEFER) -{ ... -dev_err(...); -... } | ... -dev_err(...); ) ... } // While we're here, remove braces on if statements that only have one statement (manually). Cc: linux-gpio@vger.kernel.org Cc: Greg Kroah-Hartman Signed-off-by: Stephen Boyd Link: https://lore.kernel.org/r/20190730181557.90391-16-swboyd@chromium.org Acked-by: Bartosz Golaszewski Signed-off-by: Linus Walleij

Merge tag 'gpio-v5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

2019-07-09T16:07:00Z

Pull GPIO updates from Linus Walleij: "This is the big slew of GPIO changes for the v5.3 kernel cycle. This is mostly incremental work this time. Three important things: - The FMC subsystem is deleted through my tree. This happens through GPIO as its demise was discussed in relation to a patch decoupling its GPIO implementation from the standard way of handling GPIO. As it turns out, that is not the only subsystem it reimplements and the authors think it is better do scratch it and start over using the proper kernel subsystems than try to polish the rust shiny. See the commit (ACKed by the maintainers) for details. - Arnd made a small devres patch that was ACKed by Greg and goes into the device core. - SPDX header change colissions may happen, because at times I've seen that quite a lot changed during the -rc:s in regards to SPDX. (It is good stuff, tglx has me convinced, and it is worth the occasional pain.) Apart from this is is nothing controversial or problematic. Summary: Core: - When a gpio_chip request GPIOs from itself, it can now fully control the line characteristics, both machine and consumer flags. This makes a lot of sense, but took some time before I figured out that this is how it has to work. - Several smallish documentation fixes. New drivers: - The PCA953x driver now supports the TI TCA9539. - The DaVinci driver now supports the K3 AM654 SoCs. Driver improvements: - Major overhaul and hardening of the OMAP driver by Russell King. - Starting to move some drivers to the new API passing irq_chip along with the gpio_chip when adding the gpio_chip instead of adding it separately. Unrelated: - Delete the FMC subsystem" * tag 'gpio-v5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (87 commits) Revert "gpio: tegra: Clean-up debugfs initialisation" gpiolib: Use spinlock_t instead of struct spinlock gpio: stp-xway: allow compile-testing gpio: stp-xway: get rid of the #include dependency gpio: stp-xway: improve module clock error handling gpio: stp-xway: simplify error handling in xway_stp_probe() gpiolib: Clarify use of non-sleeping functions gpiolib: Fix references to gpiod_[gs]et_*value_cansleep() variants gpiolib: Document new gpio_chip.init_valid_mask field Documentation: gpio: Fix reference to gpiod_get_array() gpio: pl061: drop duplicate printing of device name gpio: altera: Pass irqchip when adding gpiochip gpio: siox: Use devm_ managed gpiochip gpio: siox: Add struct device *dev helper variable gpio: siox: Pass irqchip when adding gpiochip drivers: gpio: amd-fch: make resource struct const devres: allow const resource arguments gpio: ath79: Pass irqchip when adding gpiochip gpio: tegra: Clean-up debugfs initialisation gpio: siox: Switch to IRQ_TYPE_NONE ...

gpio: grgpio: Use devm_platform_ioremap_resource()

2019-06-27T14:56:51Z

Use the new helper that wraps the calls to platform_get_resource() and devm_ioremap_resource() together. Signed-off-by: Enrico Weigelt, metux IT consult Signed-off-by: Linus Walleij

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman