From 5a920b85f2c6e3fd7d9dd9bb3f3345e9085e2360 Mon Sep 17 00:00:00 2001 From: Paulo Zanoni Date: Tue, 4 Oct 2016 14:37:32 -0300 Subject: [PATCH] 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 Reviewed-by: Lyude Link: http://patchwork.freedesktop.org/patch/msgid/1475602652-17326-1-git-send-email-paulo.r.zanoni@intel.com --- drivers/gpu/drm/i915/intel_pm.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 7f1748a1e614..fe6c1c61c388 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -3362,13 +3362,15 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate, int num_active; int id, i; + /* Clear the partitioning for disabled planes. */ + memset(ddb->plane[pipe], 0, sizeof(ddb->plane[pipe])); + memset(ddb->y_plane[pipe], 0, sizeof(ddb->y_plane[pipe])); + if (WARN_ON(!state)) return 0; if (!cstate->base.active) { ddb->pipe[pipe].start = ddb->pipe[pipe].end = 0; - memset(ddb->plane[pipe], 0, sizeof(ddb->plane[pipe])); - memset(ddb->y_plane[pipe], 0, sizeof(ddb->y_plane[pipe])); return 0; } @@ -4054,6 +4056,12 @@ skl_compute_ddb(struct drm_atomic_state *state) intel_state->wm_results.dirty_pipes = ~0; } + /* + * We're not recomputing for the pipes not included in the commit, so + * make sure we start with the current state. + */ + memcpy(ddb, &dev_priv->wm.skl_hw.ddb, sizeof(*ddb)); + for_each_intel_crtc_mask(dev, intel_crtc, realloc_pipes) { struct intel_crtc_state *cstate; -- 2.20.1