[Intel-gfx] [PATCH] drm/i915: Move vblank wait determination to 'check' phase

[Matt Roper]

Determining whether we'll need to wait for vblanks is something we
should determine during the atomic 'check' phase, not the 'commit'
phase.  Note that we only set these bits in the branch of 'check' where
intel_crtc->active is true so that we don't try to wait on a disabled
CRTC.

The whole 'wait for vblank after update' flag should go away in the
future, once we start handling watermarks in a proper atomic manner.

Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
Root-cause-analysis-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89550
Testcase: igt/pm_rpm/legacy-planes
Testcase: igt/pm_rpm/legacy-planes-dpms
Testcase: igt/pm_rpm/universal-planes
Testcase: igt/pm_rpm/universal-planes-dpms
Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
---
Paulo, can you test this patch and see if it solves the problem?  The only
platform I have access to (IVB) doesn't have runtime power management, so I
can't actually run the relevant testcases myself.

 drivers/gpu/drm/i915/intel_sprite.c | 24 ++++++++++--------------
 1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index a828736..fad1d9f 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -747,13 +747,6 @@ ivb_disable_plane(struct drm_plane *plane, struct drm_crtc *crtc)
 	I915_WRITE(SPRSURF(pipe), 0);
 
 	intel_flush_primary_plane(dev_priv, intel_crtc->plane);
-
-	/*
-	 * Avoid underruns when disabling the sprite.
-	 * FIXME remove once watermark updates are done properly.
-	 */
-	intel_crtc->atomic.wait_vblank = true;
-	intel_crtc->atomic.update_sprite_watermarks |= (1 << drm_plane_index(plane));
 }
 
 static int
@@ -937,13 +930,6 @@ ilk_disable_plane(struct drm_plane *plane, struct drm_crtc *crtc)
 	I915_WRITE(DVSSURF(pipe), 0);
 
 	intel_flush_primary_plane(dev_priv, intel_crtc->plane);
-
-	/*
-	 * Avoid underruns when disabling the sprite.
-	 * FIXME remove once watermark updates are done properly.
-	 */
-	intel_crtc->atomic.wait_vblank = true;
-	intel_crtc->atomic.update_sprite_watermarks |= (1 << drm_plane_index(plane));
 }
 
 /**
@@ -1262,6 +1248,16 @@ finish:
 		    plane->state->fb->modifier[0] !=
 		    state->base.fb->modifier[0])
 			intel_crtc->atomic.update_wm = true;
+
+		if (!state->visible) {
+			/*
+			 * Avoid underruns when disabling the sprite.
+			 * FIXME remove once watermark updates are done properly.
+			 */
+			intel_crtc->atomic.wait_vblank = true;
+			intel_crtc->atomic.update_sprite_watermarks |=
+				(1 << drm_plane_index(plane));
+		}
 	}
 
 	return 0;
-- 
1.8.5.1