Re: [PATCH] HID: hid-sony: Prevent LED overrun

[Frank Praznik <frank.praznik@gmail.com>]

> If the value written to led1 is larger than 1 (for SixAxis or Intec
> controllers),
> it can effect other leds on the device.
> For example:
> # echo 3 > /sys/class/leds/0003\:054C\:0268.0013\:\:sony1/brightness
>
> turns on both led1 and led2, led2 does not then behave as expected through it's
> own interface.
>
> Patch limits the LEDs 'value' to the 'max brightness', thus preventing bug.
>
> Tested with SixAxis DS3, DS4 and Intec (3rd party) controllers, via USB
> connection.
>
> Signed-off-by: Simon Wood <si...@mungewell.org>
> ---
>   drivers/hid/hid-sony.c | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/drivers/hid/hid-sony.c b/drivers/hid/hid-sony.c
> index 31e9d25..385fa1f 100644
> --- a/drivers/hid/hid-sony.c
> +++ b/drivers/hid/hid-sony.c
> @@ -1296,6 +1296,9 @@ static void sony_led_set_brightness(struct led_classdev
> *led,
>                          drv_data->led_delay_on[n] ||
>                          drv_data->led_delay_off[n]))) {
>   
> +                       if (value > led->max_brightness)
> +                               value = led->max_brightness;
> +
>                          drv_data->led_state[n] = value;
>   
>                          /* Setting the brightness stops the blinking */
> -- 
> 1.9.1

Hi Simon,

I think this was a bug in the LED system itself fixed by this commit:

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/leds/leds.h?id=56d06fdee534124f79b51ff92232373b783cddc2

In kernel 3.19 the brightness values are clamped correctly and I can't 
replicate your bug.

Regards,
Frank