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Daniel Vetter authored
Atm the crtc helper implementation of set_config has really inconsisten semantics: If just an fb update is good enough, dpms state will be left as-is, but if we do a full modeset we force everything to dpms on. This change has already been applied to the i915 modeset code in commit e3de42b6 Author: Imre Deak <imre.deak@intel.com> Date: Fri May 3 19:44:07 2013 +0200 drm/i915: force full modeset if the connector is in DPMS OFF mode which according to Greg KH seems to aim for a new record in most Bugzilla: links in a commit message. The history of this dpms forcing is pretty interesting. This patch here is an almost-revert of commit 811aaa55 Author: Keith Packard <keithp@keithp.com> Date: Thu Feb 3 16:57:28 2011 -0800 drm: Only set DPMS ON when actually configuring a mode which fixed the bug of trying to dpms on disabled outputs, but introduced the new discrepancy between an fb update only and full modesets. The actual introduction of this goes back to commit bf9dc102 Author: Keith Packard <keithp@keithp.com> Date: Fri Nov 26 10:45:58 2010 -0800 drm: Set connector DPMS status to ON in drm_crtc_helper_set_config And if you'd dig around in the i915 driver code there's even more fun around forcing dpms on and losing our heads and temper of the resulting inconsistencies. Especially the DP re-training code had tons of funny stuff in it. v2: So v1 totally blew up on resume on my radeon system here. After much head-scraching I've figured out that the radeon resume functions resumes the console system _before_ it actually restores all the modeset state. And resuming the console systems means that fbdev doeas an immediate ->set_par call. Now up to this patch that ->set_par did absolutely nothing: All the old sw state from pre-suspend was still around (since the modeset reset wasn't done yet), which means that the set_config calls done as a result of the ->set_par where all treated as no-ops (despite that the real hw state was obviously something completely different). Since v1 of this patch just added a bunch of ->dpms calls if the crtc was enabled, those set_config calls suddenly stopped being no-ops. But because the hw state wasn't restored the ->dpms callbacks resulted in decent amounts of hilarity and eventual full hangs. Since I can't review all kms drivers for such tricky ordering constraints v2 opts for a different approach and forces a full modeset if the connector dpms state isnt' DPMS_ON. Since the ->dpms callbacks implemented by the modeset helpers update the connector->dpms property we have the same effect of ensuring that the pipe is ultimately turned on, even if we just end up updating the fb. This is the same approac we ended up using in the intel driver. Note that besides i915.ko only all other drivers eventually call drm_helper_connector_dpms with the exception of vmwgfx, which does not support dmps at all. v3: Dave Airlie merged the broken first version of this patch, so squash in the revert of commit 372835a8 Author: Daniel Vetter <daniel.vetter@ffwll.ch> Date: Sat Jun 15 00:13:13 2013 +0200 drm/crtc-helper: explicit DPMS on after modeset Also fix up the spelling fail a bit in the commit message while at it. Cc: Dave Airlie <airlied@redhat.com> Reviewed-by:
Alex Deucher <alexdeucher@gmail.com> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67043Signed-off-by:
Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by:
Dave Airlie <airlied@redhat.com>
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