[PATCH 8/9] drm: Reject modes with more than 1 stereo flags set

[Damien Lespiau]

When setting a stereo 3D mode, there can be only one bit set describing
the layout of the frambuffer(s). So reject invalid modes early.

Signed-off-by: Damien Lespiau <damien.lespiau at intel.com>
---
 drivers/gpu/drm/drm_crtc.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index ff9646f..f53d199 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -1315,6 +1315,10 @@ static int drm_crtc_convert_umode(struct drm_display_mode *out,
 	if (in->clock > INT_MAX || in->vrefresh > INT_MAX)
 		return -ERANGE;
 
+	/* At most, 1 set bit describing the 3D layout of the mode */
+	if (hweight32(in->flags & DRM_MODE_FLAG_3D_MASK) > 1)
+		return -EINVAL;
+
 	out->clock = in->clock;
 	out->hdisplay = in->hdisplay;
 	out->hsync_start = in->hsync_start;
-- 
1.8.3.1