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* drm/i915: Disabling unused outputs on CPT is broken
@ 2011-08-06 17:54 Keith Packard
  2011-08-06 17:54 ` [PATCH 1/4] drm/i915: Wait for LVDS panel power sequence Keith Packard
                   ` (3 more replies)
  0 siblings, 4 replies; 18+ messages in thread
From: Keith Packard @ 2011-08-06 17:54 UTC (permalink / raw)
  To: Dave Airlie; +Cc: linux-kernel, dri-devel, intel-gfx, Keith Packard

Here's a fun sequence:

$ xrandr --output LVDS1 --auto --crtc 1
$ sudo chvt 1

(then switch back to X)

The LVDS goes black. Why? The LVDS is *disabled*. Turns out that the
cause was that after the mode was all nicely set,
intel_disable_pch_ports went and turned it back off.

Well, a couple of weeks ago, we found that intel_disable_pch_ports was
doing the same thing to DP ports, and the cause was that the way to
tell which port a DP output was running from is different on CPT that
on every other chip. We fixed that, but didn't (foolishly) review the
non-DP code.

Oddly, the non-DP code had essentially the same bug:

 [PATCH 3/4] drm/i915: Fix PCH port pipe select in CPT disable paths

Also in this sequence is some code that validates the LVDS panel power
sequencing which discovered that the LVDS panel wasn't being disabled
correctly because the LVDS registers were locked in the DPMS
function. Instead of trying to get the LVDS locking right, I've just
unlocked the registers in the lvds initialization code and left them
unlocked after that:

 [PATCH 1/4] drm/i915: Wait for LVDS panel power sequence
 [PATCH 2/4] drm/i915: Leave LVDS registers unlocked

Finally, I removed an unused argument to dp_pipe_enable while I was
poking around in that code:

 [PATCH 4/4] drm/i915: Remove unused 'reg' argument to dp_pipe_enable

--
keith.packard@intel.com

^ permalink raw reply	[flat|nested] 18+ messages in thread

end of thread, other threads:[~2011-08-08 20:25 UTC | newest]

Thread overview: 18+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-08-06 17:54 drm/i915: Disabling unused outputs on CPT is broken Keith Packard
2011-08-06 17:54 ` [PATCH 1/4] drm/i915: Wait for LVDS panel power sequence Keith Packard
2011-08-08 16:27   ` [Intel-gfx] " Jesse Barnes
2011-08-08 18:40     ` Keith Packard
2011-08-08 18:50       ` Jesse Barnes
2011-08-06 17:54 ` [PATCH 2/4] drm/i915: Leave LVDS registers unlocked Keith Packard
2011-08-08 16:30   ` Jesse Barnes
2011-08-08 18:25     ` [Intel-gfx] " Keith Packard
2011-08-08 18:42     ` Keith Packard
2011-08-08 18:49       ` [Intel-gfx] " Jesse Barnes
2011-08-08 19:53         ` Keith Packard
2011-08-08 20:01           ` Jesse Barnes
2011-08-08 20:24             ` Keith Packard
2011-08-08 20:25               ` Jesse Barnes
2011-08-06 17:54 ` [PATCH 3/4] drm/i915: Fix PCH port pipe select in CPT disable paths Keith Packard
2011-08-08 16:31   ` [Intel-gfx] " Jesse Barnes
2011-08-06 17:54 ` [PATCH 4/4] drm/i915: Remove unused 'reg' argument to dp_pipe_enabled Keith Packard
2011-08-08 16:32   ` [Intel-gfx] " Jesse Barnes

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