Commit 837b05fe authored by Bartosz Golaszewski's avatar Bartosz Golaszewski Committed by Jiri Kosina
Browse files

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



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: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.com>
parent a99548b8

drivers/hid/hid-cp2112.c

+15 −8
Original line number Diff line number Diff line
@@ -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;