Commit 1bf7ba40 authored by Kent Gibson's avatar Kent Gibson Committed by Bartosz Golaszewski
Browse files

gpiolib: cdev: remove recalculation of offset 



Remove recalculation of offset from desc, where desc itself was calculated
from offset.

There is no benefit from the desc -> hwgpio conversion in this context.
The only implicit benefit of the offset -> desc -> hwgpio is
the range check in the offset -> desc, but where desc is required you
still get that, and where desc isn't required it is simpler to perform
the range check directly.

Signed-off-by: default avatarKent Gibson <warthog618@gmail.com>
Signed-off-by: default avatarBartosz Golaszewski <bgolaszewski@baylibre.com>
parent f30ef3e8

drivers/gpio/gpiolib-cdev.c

+7 −13
Original line number Diff line number Diff line
@@ -832,7 +832,6 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 
	void __user *ip = (void __user *)arg;

	struct gpio_desc *desc;

	__u32 offset;

	int hwgpio;



	/* We fail any subsequent ioctl():s when the chip is gone */

	if (!gc)
@@ -860,12 +859,11 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 
		if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))

			return -EFAULT;



		/* this doubles as a range check on line_offset */

		desc = gpiochip_get_desc(gc, lineinfo.line_offset);

		if (IS_ERR(desc))

			return PTR_ERR(desc);



		hwgpio = gpio_chip_hwgpio(desc);



		gpio_desc_to_lineinfo(desc, &lineinfo);



		if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
@@ -881,19 +879,18 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 
		if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))

			return -EFAULT;



		/* this doubles as a range check on line_offset */

		desc = gpiochip_get_desc(gc, lineinfo.line_offset);

		if (IS_ERR(desc))

			return PTR_ERR(desc);



		hwgpio = gpio_chip_hwgpio(desc);



		if (test_and_set_bit(hwgpio, cdev->watched_lines))

		if (test_and_set_bit(lineinfo.line_offset, cdev->watched_lines))

			return -EBUSY;



		gpio_desc_to_lineinfo(desc, &lineinfo);



		if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) {

			clear_bit(hwgpio, cdev->watched_lines);

			clear_bit(lineinfo.line_offset, cdev->watched_lines);

			return -EFAULT;

		}
@@ -902,13 +899,10 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 
		if (copy_from_user(&offset, ip, sizeof(offset)))

			return -EFAULT;



		desc = gpiochip_get_desc(gc, offset);

		if (IS_ERR(desc))

			return PTR_ERR(desc);



		hwgpio = gpio_chip_hwgpio(desc);

		if (offset >= cdev->gdev->ngpio)

			return -EINVAL;



		if (!test_and_clear_bit(hwgpio, cdev->watched_lines))

		if (!test_and_clear_bit(offset, cdev->watched_lines))

			return -EBUSY;



		return 0;

CRA Git | Maintained and supported by SUSTech CRA and CCSE