Hey,

Op 20-09-16 om 20:45 schreef Mike Lothian:
> Hi
>
> I've bisected back to this commit in the drm-intel-nightly branch
>
> 05a76d3d6ad1ee9f9814f88949cc9305fc165460 is the first bad commit
> commit 05a76d3d6ad1ee9f9814f88949cc9305fc165460
> Author: Lyude <cpaul@redhat.com>
> Date:   Wed Aug 17 15:55:57 2016 -0400
>
>    drm/i915/skl: Ensure pipes with changed wms get added to the state
>
>    If we're enabling a pipe, we'll need to modify the watermarks on all
>    active planes. Since those planes won't be added to the state on
>    their own, we need to add them ourselves.
>
>    Signed-off-by: Lyude <cpaul@redhat.com>
>    Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
>    Cc: stable@vger.kernel.org
>    Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
>    Cc: Daniel Vetter <daniel.vetter@intel.com>
>    Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
>    Cc: Hans de Goede <hdegoede@redhat.com>
>    Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
>    Link: http://patchwork.freedesktop.org/patch/msgid/1471463761-26796-6-git-send-email-cpaul@redhat.com
>
> The symptoms I'm seeing look like tearing at the top of the screen and
> it's especially noticeable in Chrome - reverting this commit makes the
> issue go away
>
> Let me know if you'd like me to raise a bug
Please do so, it's nice to refer to when making a fix for it.

Could you attach the contents of /sys/kernel/debug/dri/0/i915_ddb_info for working and not-working in it?

~Maarten