|Summary:||i915: 2.6.36-rc2 hoses my Intel display|
|Product:||Drivers||Reporter:||Maciej Rutecki (maciej.rutecki)|
|Component:||Video(DRI - Intel)||Assignee:||drivers_video-dri-intel (drivers_video-dri-intel)|
|Severity:||normal||CC:||chris, corbet, eric, florian, maciej.rutecki, plroskin, rjw|
|Bug Depends on:|
that's a preliminary patch, I'm not sure all changes are needed
Description Maciej Rutecki 2010-08-26 19:11:36 UTC
Subject : i915: 2.6.36-rc2 hoses my Intel display Submitter : Jonathan Corbet <firstname.lastname@example.org> Date : 2010-08-23 17:01 Message-ID : email@example.com References : http://marc.info/?l=linux-kernel&m=128258293327326&w=2 Handled-By : Chris Wilson <firstname.lastname@example.org> This entry is being used for tracking a regression from 2.6.35. Please don't close it until the problem is fixed in the mainline. Caused by: commit 32aad86fe88e7323d4fc5e9e423abcee0d55a03d Author: Chris Wilson <email@example.com> Date: Wed Aug 4 13:50:25 2010 +0100 drm/i915/sdvo: Propagate errors from reading/writing control bus. Signed-off-by: Chris Wilson <firstname.lastname@example.org> Signed-off-by: Eric Anholt <email@example.com> First-Bad-Commit : 32aad86fe88e7323d4fc5e9e423abcee0d55a03d
Comment 1 Rafael J. Wysocki 2010-08-30 20:41:19 UTC
On Monday, August 30, 2010, Jonathan Corbet wrote: > On Mon, 30 Aug 2010 00:36:36 +0200 (CEST) > "Rafael J. Wysocki" <firstname.lastname@example.org> wrote: > > > The following bug entry is on the current list of known regressions > > from 2.6.35. Please verify if it still should be listed and let the > tracking team > > know (either way). > > > > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=17151 > > Yes, it was still definitely not working as of just a little prior to > -rc3.
Comment 2 Pavel Roskin 2010-09-01 00:45:09 UTC
I bisected the patch itself, and it looks like some checks in intel_sdvo_mode_set() are excessive. I'm attaching a preliminary patch that fixes the "blurring". It applies to 2.6.36-rc3. I didn't try to minimize changes, but I know that the change for intel_sdvo_set_input_timing() is needed, so it must be failing.
Comment 3 Pavel Roskin 2010-09-01 00:46:42 UTC
Created attachment 28721 [details] that's a preliminary patch, I'm not sure all changes are needed
Comment 4 Pavel Roskin 2010-09-01 21:23:56 UTC
Following calls are actually failing: intel_sdvo_set_value() for SDVO_CMD_SET_IN_OUT_MAP intel_sdvo_set_output_timing() intel_sdvo_set_input_timing() In all cases the status is SDVO_CMD_STATUS_NOTSUPP (not supported).
Comment 6 Chris Wilson 2010-09-02 07:45:34 UTC
Pavel, thank you for digging in and finding the cause. Error handling ftw. IN_OUT_MAP we can ignore (we can assume a single function device in that case, and since we have a static assignment we could move that to initialisation), but we should be concerned if we cannot set the output timing and handle that error by reporting the mode invalid.
Comment 7 Chris Wilson 2010-09-02 07:51:50 UTC
(In reply to comment #5) > Created an attachment (id=28782) [details] > minimal patch Yes, I think this is the minimal patch, please send it upstream to intel-gfx@ and linux-kernel@ Reported-by: Jonathan Corbet <email@example.com> Reviewed-by: Chris Wilson <firstname.lastname@example.org>
Comment 8 Pavel Roskin 2010-09-02 18:49:11 UTC
I've just sent the patch. I think silent return on error is always bad, but I leave fixing it to the code maintainers.
Comment 10 Rafael J. Wysocki 2010-09-12 18:06:41 UTC
Fixed by commit c74696b9c890074c1e1ee3d7496fc71eb3680ced .