[PATCH] pinctrl: nsp-gpio: fix type of iterator
From: rjui@broadcom.com (Ray Jui)
Date: 2015-12-23 22:36:11
Also in:
linux-gpio, lkml
+ Reddy On 12/23/2015 2:37 AM, Andrzej Hajda wrote:
quoted hunk ↗ jump to hunk
Iterator i declared as unsigned is always non-negative so the loop will never end. The problem has been detected using proposed semantic patch scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci [1]. [1]: http://permalink.gmane.org/gmane.linux.kernel/2038576 Signed-off-by: Andrzej Hajda <redacted> --- drivers/pinctrl/bcm/pinctrl-nsp-gpio.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)diff --git a/drivers/pinctrl/bcm/pinctrl-nsp-gpio.c b/drivers/pinctrl/bcm/pinctrl-nsp-gpio.c index 34648f6..ad5b04c 100644 --- a/drivers/pinctrl/bcm/pinctrl-nsp-gpio.c +++ b/drivers/pinctrl/bcm/pinctrl-nsp-gpio.c@@ -439,7 +439,8 @@ static int nsp_gpio_set_strength(struct nsp_gpio *chip, unsigned gpio, static int nsp_gpio_get_strength(struct nsp_gpio *chip, unsigned gpio, u16 *strength) { - unsigned int i, offset, shift; + unsigned int offset, shift; + int i; u32 val; unsigned long flags;
The fix is a valid fix. And at the same time it exposes other potential
issues in the driver. I just found the loop used in _set_strength and
_get_strength is inconsistent:
In _set_strength:
427 for (i = GPIO_DRV_STRENGTH_BITS; i > 0; i--) {
For i to start at GPIO_DRV_STRENGTH_BITS, it seems to be wrong.
428 val = readl(chip->io_ctrl + offset);
429 val &= ~BIT(shift);
430 val |= ((strength >> (i-1)) & 0x1) << shift;
431 writel(val, chip->io_ctrl + offset);
432 offset += 4;
433 }
In _get_strength:
451 for (i = (GPIO_DRV_STRENGTH_BITS - 1); i >= 0; i--) {
452 val = readl(chip->io_ctrl + offset) & BIT(shift);
453 val >>= shift;
454 *strength += (val << i);
455 offset += 4;
456 }
Reddy, could you please review and comment?
Thanks,
Ray