gpio-fsm: Clamp the delay time to zero

The sysfs delay_ms value is calculated live, and it is possible for
the time left to appear to be negative briefly if the timer handling
hasn't completed. Ensure the displayed value never goes below zero,
for the sake of appearances.

Signed-off-by: Phil Elwell <[email protected]>

Author: pelwell

drivers/gpio/gpio-fsm.c

@@ -884,7 +884,7 @@ static ssize_t delay_ms_show(struct device *dev,
 	const struct gpio_fsm *gf = dev_get_drvdata(dev);
 	int jiffies_left;
 
-	jiffies_left = gf->delay_jiffies - jiffies;
+	jiffies_left = max((int)(gf->delay_jiffies - jiffies), 0);
 	return sprintf(buf,
 		       gf->delay_target_state ? "%u\n" : "-\n",
 		       jiffies_to_msecs(jiffies_left));