On Wed, 01 Mar 2017, Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> 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. I think one idea was simply diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c index e144f033f4b5..0261c841756f 100644 --- a/drivers/gpu/drm/i915/intel_bios.c +++ b/drivers/gpu/drm/i915/intel_bios.c @@ -1377,10 +1377,6 @@ init_vbt_defaults(struct drm_i915_private *dev_priv) &dev_priv->vbt.ddi_port_info[port]; info->hdmi_level_shift = HDMI_LEVEL_SHIFT_UNKNOWN; - - info->supports_dvi = (port != PORT_A && port != PORT_E); - info->supports_hdmi = info->supports_dvi; - info->supports_dp = (port != PORT_E); } } --- but apparently it's problematic for machines without VBT, specifically some Chromebooks [citation needed]. Jani. > > 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. -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
