Subject: PXA PWM possible regression after 3.5: backlight remains off after resume

From: [email-masked] (Robert Jarzmik)
Date: Tue, 25 Sep 2012 21:43:39 +0200

Paul Parsons <[email-masked]> writes:

> The same failure is also present in 3.6-rc1.
>
> Just to be clear, are you saying that drivers/pwm/pwm-pxa.c should
> include suspend/resume handlers like in drivers/pwm/pwm-samsung.c ?
>
> Agreed that it is possible that recent changes exposed a latent bug
> somewhere, and that turning the backlight on after resume should never
> have worked.

Hi Paul,

I checked on the mioa701 board (see [1]).
On my board, the backlight if fully driven by PXA PWM0, and the suspend/resume
is working perfectly.

So I don't thing anything is needed for suspend/resume wrt PWM (empirically).

Cheers.

-- 
Robert

[1]
$ cat /sys/class/backlight/pwm-backlight/actual_brightness 
50
$ cat /sys/class/backlight/pwm-backlight/actual_brightness 
50
$ echo 90 > /sys/class/backlight/pwm-backlight/brightness        
$ echo mem > /sys/power/state 
$ 
$ cat /sys/class/backlight/pwm-backlight/actual_brightness 
90
$ uname -a
Linux mioa701 3.6.0-rc6+ #26 PREEMPT Sat Sep 22 22:08:41 CEST 2012 armv5tel unknown