xf86-video-intel: src/sna/sna_display.c

[Chris Wilson]

 src/sna/sna_display.c |   28 ++++++++++++++++------------
 1 file changed, 16 insertions(+), 12 deletions(-)

New commits:
commit be0fc3ce20fda064d68f38e24717552222d1fd74
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Sun Apr 5 15:46:27 2015 +0100

    sna: Block signals while releasing cursor under modeset
    
    Otherwise we may process a SIGIO moving the cursor away from the CRTC
    causing us to remove the cursor and then process a stale pointer inside
    the modeset after the signal is complete.
    
    Reported-by: Chris Bainbrigde <chris.bainbridge at gmail.com>
    References: https://bugs.freedesktop.org/show_bug.cgi?id=89903
    Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

diff --git a/src/sna/sna_display.c b/src/sna/sna_display.c
index 26660b2..6f69619 100644
--- a/src/sna/sna_display.c
+++ b/src/sna/sna_display.c
@@ -5202,24 +5202,28 @@ static void
 sna_crtc_disable_cursor(struct sna *sna, struct sna_crtc *crtc)
 {
 	struct drm_mode_cursor arg;
+	int sigio;
 
 	if (!crtc->cursor)
 		return;
 
-	DBG(("%s: CRTC:%d, handle=%d\n", __FUNCTION__, crtc->id, crtc->cursor->handle));
-	assert(crtc->cursor->ref);
+	sigio = sigio_block();
+	if (crtc->cursor) {
+		DBG(("%s: CRTC:%d, handle=%d\n", __FUNCTION__, crtc->id, crtc->cursor->handle));
+		assert(crtc->cursor->ref > 0);
+		crtc->cursor->ref--;
+		crtc->cursor = NULL;
+		crtc->last_cursor_size = 0;
 
-	VG_CLEAR(arg);
-	arg.flags = DRM_MODE_CURSOR_BO;
-	arg.crtc_id = crtc->id;
-	arg.width = arg.height = 0;
-	arg.handle = 0;
+		VG_CLEAR(arg);
+		arg.flags = DRM_MODE_CURSOR_BO;
+		arg.crtc_id = crtc->id;
+		arg.width = arg.height = 0;
+		arg.handle = 0;
 
-	(void)drmIoctl(sna->kgem.fd, DRM_IOCTL_MODE_CURSOR, &arg);
-	assert(crtc->cursor->ref > 0);
-	crtc->cursor->ref--;
-	crtc->cursor = NULL;
-	crtc->last_cursor_size = 0;
+		(void)drmIoctl(sna->kgem.fd, DRM_IOCTL_MODE_CURSOR, &arg);
+	}
+	sigio_unblock(sigio);
 }
 
 static void