Re: [PATCH v2 0/4] fujitsu_init() cleanup
From: Jonathan Woithe
Date: Mon Mar 06 2017 - 03:55:33 EST
Hi Michael
Some quick feedback.
On Mon, Mar 06, 2017 at 03:31:04PM +1030, Jonathan Woithe wrote:
> > > I can add that immediately after loading the driver the value returned by a
> > > read of bl_power is 0. As noted above, setting to 1 makes no difference to
> > > the backlight, neither does returning it to 0.
> >
> > Have you tried setting bl_power to 4? Because that is the value of
> > FB_BLANK_POWERDOWN, which is the value the patch is supposed to handle.
>
> Oh no, I didn't try 4. I should have. I will try to squeeze in a test of
> this tonight (time is short but the test won't take a lot of time).
With an unpatched 4.5 kernel, writing 4 (as opposed to 1, which I stupidly
tried earlier) to bl_power caused the backlight to turn off. Writing 0
turned it back on again.
With patches 1-4/4 applied, writing 4 to bl_power did *NOT* turn the
backlight off.
With patch 2 reverted, writing 4 to bl_power turned the backlight off.
Writing 0 to bl_power turned it back on again.
This means that patch 2/4 seems to prevent bl_power from operating as
expected on the S7020 hardware. Without this patch (but with all the others
in place) bl_power works.
I am unlikely to have any more time to investigate this further tonight.
In light of the above findings, what would you like to do?
Regards
jonathan