problem configuring backlight brightness levels in device tree

Sascha Hauer s.hauer at pengutronix.de
Tue Jul 12 22:18:05 PDT 2016


On Mon, Jul 11, 2016 at 01:51:11PM +0200, giorgio.nicole at arcor.de wrote:
> Hi,
> 
> I was trying to configure a pwm backlight on an embedded arm board
> and I think I've found a minor problem.
> 
> In the source file 'drivers/video/backlight-pwm.c', in the function pwm_backlight_parse_dt()
> you set the number of brightness values to:
> 
> pwm_backlight->backlight.brightness_max = length / sizeof(u32);
> 
> and then loop through the array with:
> 
> for (i = 0; i <=  pwm_backlight->backlight.brightness_max; i++)
> 
> to find the max of the array.
> 
> I think the '<=' should be a '<' otherwise you access an uninitialized value
> one past the end of the array; this actually does not directly crash barebox
> but the whole brightness values are scaled wrong.

Yes, you're right. Can you send a patch for this?

Sascha

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |



More information about the barebox mailing list