[Intel-gfx] [PATCH 2/3] drm/i915: Use the correct crtc when sanitizing plane mapping

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

When we decide that a plane is attached to the wrong pipe we try
to turn off said plane. However we are passing around the crtc we
think that the plane is supposed to be using rather than the crtc
it is currently using. That doesn't work all that well because
we may have to do vblank waits etc. and the other pipe might
not even be enabled here. So let's pass the plane's current crtc to
intel_plane_disable_noatomic() so that it can its job correctly.

To do that semi-cleanly we also have to change the plane readout
to record the plane's visibility into the bitmasks of the crtc
where the plane is currently enabled rather than to the crtc
we want to use for the plane.

One caveat here is that our active_planes bitmask will get confused
if both planes are enabled on the same pipe. Fortunately we can use
plane_mask to reconstruct active_planes sufficiently since
plane_mask still has the same meaning (is the plane visible?)
during readout. We also have to do the same during the initial
plane readout as the second plane could clear the active_planes
bit the first plane had already set.

Cc: stable at vger.kernel.org # fcba862e8428 drm/i915: Have plane->get_hw_state() return the current pipe
Cc: stable at vger.kernel.org
Cc: Dennis <dennis.nezic at utoronto.ca>
Tested-by: Dennis <dennis.nezic at utoronto.ca>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105637
Fixes: b1e01595a66d ("drm/i915: Redo plane sanitation during readout")
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 63 +++++++++++++++++++++++++++---------
 1 file changed, 47 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index e018b37bed39..c72be8cd1f54 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -15475,15 +15475,16 @@ void i830_disable_pipe(struct drm_i915_private *dev_priv, enum pipe pipe)
 	POSTING_READ(DPLL(pipe));
 }
 
-static bool intel_plane_mapping_ok(struct intel_crtc *crtc,
-				   struct intel_plane *plane)
+static void fixup_active_planes(struct intel_crtc *crtc)
 {
-	enum pipe pipe;
-
-	if (!plane->get_hw_state(plane, &pipe))
-		return true;
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+	struct intel_crtc_state *crtc_state =
+		to_intel_crtc_state(crtc->base.state);
+	struct drm_plane *plane;
 
-	return pipe == crtc->pipe;
+	drm_for_each_plane_mask(plane, &dev_priv->drm,
+				crtc_state->base.plane_mask)
+		crtc_state->active_planes |= BIT(to_intel_plane(plane)->id);
 }
 
 static void
@@ -15497,13 +15498,28 @@ intel_sanitize_plane_mapping(struct drm_i915_private *dev_priv)
 	for_each_intel_crtc(&dev_priv->drm, crtc) {
 		struct intel_plane *plane =
 			to_intel_plane(crtc->base.primary);
+		struct intel_crtc *plane_crtc;
+		enum pipe pipe;
+
+		if (!plane->get_hw_state(plane, &pipe))
+			continue;
 
-		if (intel_plane_mapping_ok(crtc, plane))
+		if (pipe == crtc->pipe)
 			continue;
 
 		DRM_DEBUG_KMS("%s attached to the wrong pipe, disabling plane\n",
 			      plane->base.name);
-		intel_plane_disable_noatomic(crtc, plane);
+
+		plane_crtc = intel_get_crtc_for_pipe(dev_priv, pipe);
+		intel_plane_disable_noatomic(plane_crtc, plane);
+
+		/*
+		 * Our active_planes tracking will get confused here
+		 * if both planes A and B are enabled on the same pipe
+		 * (since both planes map to BIT(PLANE_PRIMARY)).
+		 * Reconstruct active_planes after disabling the plane.
+		 */
+		fixup_active_planes(plane_crtc);
 	}
 }
 
@@ -15671,23 +15687,38 @@ void i915_redisable_vga(struct drm_i915_private *dev_priv)
 }
 
 /* FIXME read out full plane state for all planes */
-static void readout_plane_state(struct intel_crtc *crtc)
+static void readout_plane_state(struct drm_i915_private *dev_priv)
 {
-	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
-	struct intel_crtc_state *crtc_state =
-		to_intel_crtc_state(crtc->base.state);
 	struct intel_plane *plane;
+	struct intel_crtc *crtc;
 
-	for_each_intel_plane_on_crtc(&dev_priv->drm, crtc, plane) {
+	for_each_intel_plane(&dev_priv->drm, plane) {
 		struct intel_plane_state *plane_state =
 			to_intel_plane_state(plane->base.state);
+		struct intel_crtc_state *crtc_state;
 		enum pipe pipe;
 		bool visible;
 
 		visible = plane->get_hw_state(plane, &pipe);
 
+		crtc = intel_get_crtc_for_pipe(dev_priv, pipe);
+		crtc_state = to_intel_crtc_state(crtc->base.state);
+
 		intel_set_plane_visible(crtc_state, plane_state, visible);
 	}
+
+	for_each_intel_crtc(&dev_priv->drm, crtc) {
+		/*
+		 * Our active_planes tracking may get confused here
+		 * on gen2/3 if the first plane is enabled but the
+		 * second one isn't but both indicate the same pipe.
+		 * The second plane would clear the active_planes
+		 * bit for the first plane (since both map to
+		 * BIT(PLANE_PRIMARY). Reconstruct active_planes
+		 * after plane readout is done.
+		 */
+		fixup_active_planes(crtc);
+	}
 }
 
 static void intel_modeset_readout_hw_state(struct drm_device *dev)
@@ -15719,13 +15750,13 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
 		if (crtc_state->base.active)
 			dev_priv->active_crtcs |= 1 << crtc->pipe;
 
-		readout_plane_state(crtc);
-
 		DRM_DEBUG_KMS("[CRTC:%d:%s] hw state readout: %s\n",
 			      crtc->base.base.id, crtc->base.name,
 			      enableddisabled(crtc_state->base.active));
 	}
 
+	readout_plane_state(dev_priv);
+
 	for (i = 0; i < dev_priv->num_shared_dpll; i++) {
 		struct intel_shared_dpll *pll = &dev_priv->shared_dplls[i];
 
-- 
2.16.4