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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: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
This commit is contained in:
Kent Gibson 2020-07-08 12:15:54 +08:00 committed by Bartosz Golaszewski
parent f30ef3e837
commit 1bf7ba4001
1 changed files with 7 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
drivers/gpio/gpiolib-cdev.c
View File

@ -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);
if (offset >= cdev->gdev->ngpio)
return -EINVAL;
hwgpio = gpio_chip_hwgpio(desc);
if (!test_and_clear_bit(hwgpio, cdev->watched_lines))
if (!test_and_clear_bit(offset, cdev->watched_lines))
return -EBUSY;
return 0;