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HID: cp2112: hold the lock for the entire direction_output() call

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We currently take the lock, set direction to output, release it,
reacquire it and set the desired value. That doesn't look correct.
Introduce a helper function that sets the value without taking the lock
and use it where applicable in order to combine the critical sections.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
This commit is contained in:
Bartosz Golaszewski 2025-04-23 10:55:40 +02:00 committed by Jiri Kosina
parent a99548b834
commit 837b05fea0
1 changed files with 15 additions and 8 deletions
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23
drivers/hid/hid-cp2112.c
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@ -17,6 +17,7 @@
*/
#include <linux/bitops.h>
#include <linux/cleanup.h>
#include <linux/gpio/driver.h>
#include <linux/hid.h>
#include <linux/hidraw.h>
@ -218,15 +219,13 @@ static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
return ret;
}
static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
static void cp2112_gpio_set_unlocked(struct cp2112_device *dev,
unsigned int offset, int value)
{
struct cp2112_device *dev = gpiochip_get_data(chip);
struct hid_device *hdev = dev->hdev;
u8 *buf = dev->in_out_buffer;
int ret;
mutex_lock(&dev->lock);
buf[0] = CP2112_GPIO_SET;
buf[1] = value ? CP2112_GPIO_ALL_GPIO_MASK : 0;
buf[2] = BIT(offset);
@ -236,8 +235,16 @@ static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
HID_REQ_SET_REPORT);
if (ret < 0)
hid_err(hdev, "error setting GPIO values: %d\n", ret);
}
mutex_unlock(&dev->lock);
static void cp2112_gpio_set(struct gpio_chip *chip, unsigned int offset,
int value)
{
struct cp2112_device *dev = gpiochip_get_data(chip);
guard(mutex)(&dev->lock);
return cp2112_gpio_set_unlocked(dev, offset, value);
}
static int cp2112_gpio_get_all(struct gpio_chip *chip)
@ -306,13 +313,13 @@ static int cp2112_gpio_direction_output(struct gpio_chip *chip,
goto fail;
}
mutex_unlock(&dev->lock);
/*
* Set gpio value when output direction is already set,
* as specified in AN495, Rev. 0.2, cpt. 4.4
*/
cp2112_gpio_set(chip, offset, value);
cp2112_gpio_set_unlocked(dev, offset, value);
mutex_unlock(&dev->lock);
return 0;