drm/mgag200: Reject non-character-cell-aligned mode widths

[ Upstream commit 25161084b1c1b0c29948f6f77266a35f302196b7 ]

Turns out 1366x768 does not in fact work on this hardware.

Signed-off-by: Adam Jackson <ajax@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c
index 83485ab81ce8714214c258b537fd1609e12bae2a..d8e693d1f6d44cd5d0215498c625930e4243a3a3 100644 (file)
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -1525,6 +1525,11 @@ static int mga_vga_mode_valid(struct drm_connector *connector,
                return MODE_BANDWIDTH;
        }
 
+       if ((mode->hdisplay % 8) != 0 || (mode->hsync_start % 8) != 0 ||
+           (mode->hsync_end % 8) != 0 || (mode->htotal % 8) != 0) {
+               return MODE_H_ILLEGAL;
+       }
+
        if (mode->crtc_hdisplay > 2048 || mode->crtc_hsync_start > 4096 ||
            mode->crtc_hsync_end > 4096 || mode->crtc_htotal > 4096 ||
            mode->crtc_vdisplay > 2048 || mode->crtc_vsync_start > 4096 ||