uxa/present: Do not allow the unflip to fail

As we cannot propagate the failure for unflipping back to the caller, we
must ensure that the CRTCs are correctly reset if the attempt to flip
back to normality fails.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 14 insertions, 10 deletions

diff --git a/src/uxa/intel_present.c b/src/uxa/intel_present.c
index d20043f3..2e57e7a2 100644
--- a/src/uxa/intel_present.c
+++ b/src/uxa/intel_present.c
@@ -343,29 +343,33 @@ intel_present_unflip(ScreenPtr screen, uint64_t event_id)
 {
 	ScrnInfoPtr                             scrn = xf86ScreenToScrn(screen);
 	intel_screen_private                    *intel = intel_get_screen_private(scrn);
-	struct intel_present_vblank_event       *event;
 	PixmapPtr                               pixmap = screen->GetScreenPixmap(screen);
+	struct intel_present_vblank_event       *event = NULL;
 	dri_bo                                  *bo;
-	Bool                                    ret;
 
 	if (!intel_present_check_flip(NULL, screen->root, pixmap, true))
-		return;
+		goto fail;
 
 	bo = intel_get_pixmap_bo(pixmap);
 	if (!bo)
-		return;
+		goto fail;
 
 	event = calloc(1, sizeof(struct intel_present_vblank_event));
 	if (!event)
-		return;
+		goto fail;
 
 	event->event_id = event_id;
 
-	ret = intel_do_pageflip(intel, bo, -1, FALSE, event, intel_present_flip_event, intel_present_flip_abort);
-	if (!ret) {
-		xf86DrvMsg(scrn->scrnIndex, X_ERROR,
-			   "present unflip failed\n");
-	}
+	if (intel_do_pageflip(intel, bo, -1, FALSE, event,
+			      intel_present_flip_event,
+			      intel_present_flip_abort))
+		goto fail;
+
+	return;
+fail:
+	xf86SetDesiredModes(scrn);
+	present_event_notify(event_id, 0, 0);
+	free(event);
 }
 
 static present_screen_info_rec intel_present_screen_info = {