From 23baedd217effd594bdf4620c1fea4d27febe090 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 28 Feb 2020 22:35:50 +0200 Subject: [PATCH] drm/i915: Don't check for wm changes until we've compute the wms fully MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Currently we're comparing the watermarks between the old and new states before we've fully computed the new watermarks. In particular skl_build_pipe_wm() will not account for the amount of ddb space we'll have. That information is only available during skl_compute_ddb() which will proceed to zero out any watermark level exceeding the ddb allocation. If we're short on ddb space this will end up adding the plane to the state due erronously determining that the watermarks have changed. Fix the problem by deferring skl_wm_add_affected_planes() until we have the final watermarks computed. Noticed this when trying enable transition watermarks on glk. We now computed the trans_wm as 28, but we only had 14 blocks of ddb, and thus skl_compute_ddb() ended up disabling the cursor trans_wm every time. Thus we ended up adding the cursor to every commit that didn't actually affect the cursor at all. Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20200228203552.30273-2-ville.syrjala@linux.intel.com Reviewed-by: José Roberto de Souza --- drivers/gpu/drm/i915/intel_pm.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 43c8081ff051..b02cb0033237 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -5766,16 +5766,24 @@ skl_compute_wm(struct intel_atomic_state *state) ret = skl_build_pipe_wm(new_crtc_state); if (ret) return ret; - - ret = skl_wm_add_affected_planes(state, crtc); - if (ret) - return ret; } ret = skl_compute_ddb(state); if (ret) return ret; + /* + * skl_compute_ddb() will have adjusted the final watermarks + * based on how much ddb is available. Now we can actually + * check if the final watermarks changed. + */ + for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state, + new_crtc_state, i) { + ret = skl_wm_add_affected_planes(state, crtc); + if (ret) + return ret; + } + skl_print_wm_changes(state); return 0; -- 2.30.2