On Wed, Mar 01, 2017 at 07:56:26PM +0200, Ville Syrjälä wrote: > On Wed, Mar 01, 2017 at 07:35:15PM +0200, Jani Nikula wrote: > > On Wed, 01 Mar 2017, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > > > On Wed, Mar 01, 2017 at 06:17:49PM +0100, Daniel Vetter wrote: > > >> This reverts commit 233ce881dd91fb13eb6b09deefae33168e6ead4c. > > >> > > >> I assumed it's ok, but really should have double-checked - CI caught > > >> tons of fail :( > > > > Considering the velocity of drm-tip, I think any CI results for patches > > have a rather limited best before date. The patch should've been resent > > and gone through testing again before merging. > > > > > For the record, the failure comes from the error message in > > > intel_dp_get_link_train_fallback_values() as take the fallback path. As > > > userspace is informed, we don't need an *ERROR* at that point. > > > > > > The really interesting question is why we are seeing link-training > > > failures in CI at all, and whether igt should be checking and reporting > > > link-status=BAD. > > > > It's possible (I didn't check the logs) this pertains to the failure > > mode I've sometimes seen, where clock recovery fails, but as we continue > > with channel equalization anyway (without this patch), everything > > succeeds there. At worst we need to root cause and fix that issue > > first. :( > > The skl case seems pretty clear. We register DP for both port A and port > E even though we should register it only for port E (I think). They > both end up both using AUX A and so we think the same sink is connected > to both, and then we try to enable port A which fail for obvious reasons. > > The culprit is init_vbt_defaults() which always sets .supports_dp=true > for port A unless later overridden by the VBT. In this case the VBT has > no port A, so we leave the .supports_dp flag set. So presumably we > should just nuke this stuff from init_vbt_defaults(). > > IIRC this was discussed at some point between Imre and Paulo, but I > can't remember what the conclusion was, or if in fact there was one. > > The ilk failure case is a lot less clear. It's one of those cases > where the sink just keeps requesting the same vswing/preemph all > the time. I've seen it sometime in the past, but I've never been > able to figure out what has caused it to happen with any specific > sink. Looks like starting with: [ 3.621706] [drm:drm_dp_i2c_do_msg] I2C nack (result=0, size=1 [ 3.622794] [drm:drm_dp_i2c_do_msg] I2C nack (result=0, size=1 [ 3.623836] [drm:drm_dp_i2c_do_msg] I2C nack (result=0, size=1 [ 3.624903] [drm:drm_dp_i2c_do_msg] I2C nack (result=0, size=1 [ 3.625983] [drm:drm_dp_i2c_do_msg] I2C nack (result=0, size=1 and so failing to read out EDID. As a result we'll use the default 1024x768 which fails. In the working case we use the native 1920x1200 which succeeds. Could be that 1024x768 didn't work even before? I can't see how the patch would affect the I2C transfers. --Imre > > -- > Ville Syrjälä > Intel OTC _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
