Messages in this thread | | | Date | Tue, 17 Nov 2015 09:15:05 +0100 | From | Jacek Anaszewski <> | Subject | Re: [PATCH 1/2 (v2)] leds-bcm6328: Reuse bcm6328_led_set() instead of copying its functionality |
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On 11/17/2015 09:06 AM, Jacek Anaszewski wrote: > Hi Alvaro, Simon, > > On 11/17/2015 08:42 AM, Simon Arlott wrote: >> On 16/11/15 21:33, Álvaro Fernández Rojas wrote: >>> Still wrong, you are setting the led value after unlocking the spinlock. >> >> I have to unlock it because bcm6328_led_set() locks that spinlock. > > Commit message from the first version of the patch justified that > properly. It should be preserved in the final patch: > > As bcm6328_led_set() expects to acquire the spinlock, narrow the locking > to only cover reading of the current state. There is no need to hold the > spinlock between reading the current value and setting it again because > the LED device has not yet been registered.
Hmm, if so, then spin_lock in bcm6328_led isn't needed at all, as it is guaranteed that no concurrent process will be executing this function.
>>> El 16/11/2015 a las 21:24, Simon Arlott escribió: >>>> When ensuring a consistent initial LED state in bcm6328_led (as they >>>> may >>>> be blinking instead of on/off), the LED register is set using an >>>> inverted >>>> copy of bcm6328_led_set(). To avoid further errors relating to >>>> active low >>>> handling, call this function directly instead. >>>> >>>> As bcm6328_led_set() acquires the same spinlock again when updating the >>>> register, it is called after unlocking. >>>> >>>> Signed-off-by: Simon Arlott <simon@fire.lp0.eu> >>>> --- >>>> drivers/leds/leds-bcm6328.c | 8 ++------ >>>> 1 file changed, 2 insertions(+), 6 deletions(-) >>>> >>>> diff --git a/drivers/leds/leds-bcm6328.c b/drivers/leds/leds-bcm6328.c >>>> index c7ea5c6..95d0cf9 100644 >>>> --- a/drivers/leds/leds-bcm6328.c >>>> +++ b/drivers/leds/leds-bcm6328.c >>>> @@ -314,14 +314,10 @@ static int bcm6328_led(struct device *dev, >>>> struct device_node *nc, u32 reg, >>>> } else { >>>> led->cdev.brightness = LED_OFF; >>>> } >>>> - >>>> - if ((led->active_low && led->cdev.brightness == LED_FULL) || >>>> - (!led->active_low && led->cdev.brightness == LED_OFF)) >>>> - bcm6328_led_mode(led, BCM6328_LED_MODE_ON); >>>> - else >>>> - bcm6328_led_mode(led, BCM6328_LED_MODE_OFF); >>>> spin_unlock_irqrestore(lock, flags); >>>> >>>> + bcm6328_led_set(&led->cdev, led->cdev.brightness); >>>> + >>>> led->cdev.brightness_set = bcm6328_led_set; >>>> led->cdev.blink_set = bcm6328_blink_set; >>>> >>> >> >> > >
-- Best Regards, Jacek Anaszewski
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