On Mon, 10 Nov 2014, Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> wrote: > On Mon, 3 Nov 2014 11:39:24 +0100 > Daniel Vetter <daniel.vetter@xxxxxxxx> wrote: > >> On pre-ddi platforms we don't shut down the link when changing link >> training parameters. Except when clock recovery fails too hard and we >> restart with channel eq training. Which doesn't make a lot of sense >> really, since just stopping/restarting the DP port at this point >> violates the modeset sequence documented in the Bspec. >> >> So let's tempt fate and try this. >> >> This patch is motivated by a WARN_ON triggered by >> >> commit bc76e320f21f8bd790a72bd5dc06909617432352 >> Author: Daniel Vetter <daniel.vetter@xxxxxxxx> >> Date: Tue May 20 22:46:50 2014 +0200 >> >> drm/i915: Drop now misleading DDI comment from dp_link_down >> >> References: https://bugs.freedesktop.org/show_bug.cgi?id=85670 >> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> >> --- >> drivers/gpu/drm/i915/intel_dp.c | 1 - >> 1 file changed, 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/i915/intel_dp.c >> b/drivers/gpu/drm/i915/intel_dp.c index f6a3fdd5589e..e48ca3a87199 >> 100644 --- a/drivers/gpu/drm/i915/intel_dp.c >> +++ b/drivers/gpu/drm/i915/intel_dp.c >> @@ -3598,7 +3598,6 @@ intel_dp_complete_link_train(struct intel_dp >> *intel_dp) >> /* Try 5 times, then try clock recovery if that >> fails */ if (tries > 5) { >> - intel_dp_link_down(intel_dp); >> intel_dp_start_link_train(intel_dp); >> intel_dp_set_link_train(intel_dp, &DP, >> training_pattern | > > > Didn't look like it helped the reporter? Or at least I didn't see it > tried in the bug above... This wouldn't fix the bug, this would fix the backtrace from WARN_ON(HAS_DDI(dev)) in intel_dp_link_down that's also present in the bug. Just one more item in the long list of things that suck about our DP link training. BR, Jani. > > I'm a bit worried about this because istr the spec indicating that we > do need to down the link when retrying clock recovery. I guess I'll > need to check again. > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
