Re: [git pull] drm for rc1

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Tue, 11 Jan 2011 11:25:39 -0800
Linus Torvalds <torvalds@linux-foundation.org> wrote:

> On Tue, Jan 11, 2011 at 11:12 AM, Jesse Barnes <jbarnes@virtuousgeek.org> wrote:
> >
> > Have you tried reproducing it using xset dpms force off or similar?
> 
> That doesn't seem to do anything bad.
> 
> In fact, I think the second time it happened the screen never went
> black - just the random photo thing was on. But no, forcing the screen
> saver on doesn't do it either (ie pressing the "lock screen" icon and
> waiting for a few pictures to cycle).
> 
> Maybe the screen just has to be inactive for a longer time: do you do
> some dynamic "let's power things down if nothing is changing"?

There are some timeouts, the FBC engine will recompress about once
every 15s; the self-refresh timers are much smaller though so it should
be active anytime the CPU enters a deep sleep state.  The clock
frequency changes in millisecond time too, you can check the status of
that in /sys/kernel/debug/dri/0/i915_drpc_status and i915_cur_delayinfo.

I wonder if re-enabling rc6 may have caused your issues?  That would be:

commit 29a15061ff5df5bf9bf49c05c17f41eb2807a55a
Author: Jesse Barnes <jbarnes@virtuousgeek.org>
Date:   Wed Jan 5 12:01:24 2011 -0800

    drm/i915: re-enable rc6 support for Ironlake+

-- 
Jesse Barnes, Intel Open Source Technology Center