kernel.git/drivers/input/keyboard/gpio_keys.c, branch linux-5.14.y

Input: gpio-keys - fix crash when disabliing GPIO-less buttons

2021-04-08T06:20:52Z

My brain-damaged adjustments to Paul's patch caused crashes in gpio_keys_disable_button() when driver is used in GPIO-less (i.e. purely interrupt-driven) setups, because I mixed together debounce and release timers when they are in fact separate: Unable to handle kernel NULL pointer dereference at virtual address 0000000c ... PC is at hrtimer_active+0xc/0x98 LR is at hrtimer_try_to_cancel+0x24/0x140 ... [] (hrtimer_active) from [] (hrtimer_try_to_cancel+0x24/0x140) [] (hrtimer_try_to_cancel) from [] (hrtimer_cancel+0x14/0x4c) [] (hrtimer_cancel) from [] (gpio_keys_attr_store_helper+0x1b8/0x1d8 [gpio_keys]) [] (gpio_keys_attr_store_helper [gpio_keys]) from [] (gpio_keys_store_disabled_keys+0x18/0x24 [gpio_keys]) [] (gpio_keys_store_disabled_keys [gpio_keys]) from [] (kernfs_fop_write_iter+0x10c/0x1cc) [] (kernfs_fop_write_iter) from [] (vfs_write+0x2ac/0x404) [] (vfs_write) from [] (ksys_write+0x64/0xdc) [] (ksys_write) from [] (ret_fast_syscall+0x0/0x58) Let's fix it up. Fixes: c9efb0ba281e ("Input: gpio-keys - use hrtimer for software debounce, if possible") Reported-by: Tony Lindgren Tested-by: Tony Lindgren Link: https://lore.kernel.org/r/YG1DFFgojSVfdpaz@google.com Signed-off-by: Dmitry Torokhov

Input: gpio-keys - use hrtimer for software debounce, if possible

2021-03-25T18:14:08Z

We want to be able to report the input event as soon as the debounce delay elapsed. However, the current code does not really ensure that, as it uses the jiffies-based schedule_delayed_work() API. With a small enough HZ value (HZ <= 100), this results in some input events being lost, when a key is quickly pressed then released (on a human's time scale). Switching to hrtimers fixes this issue, and will work even on extremely low HZ values (tested at HZ=24). This is however only possible if reading the GPIO is possible without sleeping. If this condition is not met, the previous approach of using a jiffies-based timer is taken. Signed-off-by: Paul Cercueil Link: https://lore.kernel.org/r/20210307222240.380583-3-paul@crapouillou.net Signed-off-by: Dmitry Torokhov

Input: gpio-keys - use hrtimer for release timer

2021-03-25T18:14:08Z

Dealing with input, timing is important; if the button should be released in one millisecond, then it should be done in one millisecond and not a hundred milliseconds. Therefore, the standard timer API is not really suitable for this task. Convert the gpio-keys driver to use a hrtimer instead of the standard timer to address this issue. Note that by using a hard IRQ for the hrtimer callback, we can get rid of the spin_lock_irqsave() and spin_unlock_irqrestore(). Signed-off-by: Paul Cercueil Link: https://lore.kernel.org/r/20210307222240.380583-2-paul@crapouillou.net Signed-off-by: Dmitry Torokhov

Input: gpio-keys - remove extra call to input_sync

2021-03-25T18:14:08Z

The input_sync() function is already called after the loop in gpio_keys_report_state(), so it does not need to be called after each iteration within gpio_keys_gpio_report_event(). Signed-off-by: Paul Cercueil Link: https://lore.kernel.org/r/20210307222240.380583-1-paul@crapouillou.net Signed-off-by: Dmitry Torokhov

Input: use input_device_enabled()

2020-12-03T06:10:33Z

Use the newly added helper in relevant input drivers. Signed-off-by: Andrzej Pietrasiewicz Link: https://lore.kernel.org/r/20200608112211.12125-3-andrzej.p@collabora.com Signed-off-by: Dmitry Torokhov

Input: gpio_keys - fix misnamed function parameter 'dev'

2020-11-09T06:23:59Z

Fixes the following W=1 kernel build warning(s): drivers/input/keyboard/gpio_keys.c:119: warning: Function parameter or member 'dev' not described in 'get_bm_events_by_type' drivers/input/keyboard/gpio_keys.c:119: warning: Excess function parameter 'input' description in 'get_bm_events_by_type' Signed-off-by: Lee Jones Link: https://lore.kernel.org/r/20201104162427.2984742-12-lee.jones@linaro.org Signed-off-by: Dmitry Torokhov

Input: Use fallthrough pseudo-keyword

2020-07-07T18:25:54Z

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva Link: https://lore.kernel.org/r/20200707180857.GA30600@embeddedor Signed-off-by: Dmitry Torokhov

Input: gpio_keys - replace zero-length array with flexible-array member

2020-02-14T01:09:47Z

The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva Link: https://lore.kernel.org/r/20200213002600.GA31916@embeddedor.com Signed-off-by: Dmitry Torokhov

Input: gpio_keys - switch to using devm_fwnode_gpiod_get()

2019-10-27T18:12:47Z

devm_fwnode_get_gpiod_from_child() is going away as the name is too unwieldy, let's switch to using the new devm_fwnode_gpiod_get(). Signed-off-by: Dmitry Torokhov

Input: gpio_keys - convert driver to use dev_groups

2019-08-12T07:02:38Z

Drivers now have the option to have the driver core create and remove any needed sysfs attribute files. So take advantage of that and do not register "by hand" a bunch of sysfs files. Signed-off-by: Greg Kroah-Hartman Signed-off-by: Dmitry Torokhov