Commits
Paulo Zanoni committed 01c72d6c17d
drm/i915/gen9: fix DDB partitioning for multi-screen cases With the previous code we were only recomputing the DDB partitioning for the CRTCs included in the atomic commit, so any other active CRTCs would end up having their DDB registers zeroed. In this patch we make sure that the computed state starts as a copy of the current partitioning, and then we only zero the DDBs that we're actually going to recompute. How to reproduce the bug: 1 - Enable the primary plane on pipe A 2 - Enable the primary plane on pipe B 3 - Enable the cursor or sprite plane on pipe A Step 3 will zero the DDB partitioning for pipe B since it's not included in the commit that enabled the cursor or sprite for pipe A. I expect this to fix many FIFO underrun problems on gen9+. v2: - Mention the cursor on the steps to reproduce the problem (Paulo). - Add Testcase tag provided by Maarten (Maarten). Testcase: kms_cursor_legacy.cursorA-vs-flipB-atomic-transitions Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96226 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96828 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97450 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97596 Bugzilla: https://www.phoronix.com/scan.php?page=news_item&px=Intel-Skylake-Multi-Screen-Woes Cc: stable@vger.kernel.org Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> Reviewed-by: Lyude <cpaul@redhat.com> Link: http://patchwork.freedesktop.org/patch/msgid/1475602652-17326-1-git-send-email-paulo.r.zanoni@intel.com (cherry picked from commit 5a920b85f2c6e3fd7d9dd9bb3f3345e9085e2360) Signed-off-by: Jani Nikula <jani.nikula@intel.com>