Backmerge drm-fixes merge into Linus's tree into drm-next.

This merges '5b726e06d6e8309e5c9ef4109a32caf27c71dfc8' into drm-next

Just to resolve some merges to make Daniel's life easier.

Signed-off-by: DAve Airlie <airlied@redhat.com>

1 files changed, 19 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index abd2d2944022..02f6ccb848a9 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -14059,6 +14059,7 @@ intel_check_cursor_plane(struct drm_plane *plane,
 	struct drm_crtc *crtc = crtc_state->base.crtc;
 	struct drm_framebuffer *fb = state->base.fb;
 	struct drm_i915_gem_object *obj = intel_fb_obj(fb);
+	enum pipe pipe = to_intel_plane(plane)->pipe;
 	unsigned stride;
 	int ret;
 
@@ -14092,6 +14093,22 @@ intel_check_cursor_plane(struct drm_plane *plane,
 		return -EINVAL;
 	}
 
+	/*
+	 * There's something wrong with the cursor on CHV pipe C.
+	 * If it straddles the left edge of the screen then
+	 * moving it away from the edge or disabling it often
+	 * results in a pipe underrun, and often that can lead to
+	 * dead pipe (constant underrun reported, and it scans
+	 * out just a solid color). To recover from that, the
+	 * display power well must be turned off and on again.
+	 * Refuse the put the cursor into that compromised position.
+	 */
+	if (IS_CHERRYVIEW(plane->dev) && pipe == PIPE_C &&
+	    state->visible && state->base.crtc_x < 0) {
+		DRM_DEBUG_KMS("CHV cursor C not allowed to straddle the left screen edge\n");
+		return -EINVAL;
+	}
+
 	return 0;
 }
 
@@ -14124,7 +14141,8 @@ intel_commit_cursor_plane(struct drm_plane *plane,
 
 	intel_crtc->cursor_addr = addr;
 
-	intel_crtc_update_cursor(crtc, state->visible);
+	if (crtc->state->active)
+		intel_crtc_update_cursor(crtc, state->visible);
 }
 
 static struct drm_plane *intel_cursor_plane_create(struct drm_device *dev,