From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: Sun, 21 Apr 2013 23:38:46 +0000 (+0200)
Subject: drm: Don't allow page flip to change pixel format
X-Git-Tag: v4.0~4020^2~60
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=909d9cda2edfc61b8ec82e248eee3545b592e20d;p=platform%2Fkernel%2Flinux-amlogic.git

drm: Don't allow page flip to change pixel format

A page flip is not a mode set, changing the frame buffer pixel format
doesn't make sense and isn't handled by most drivers anyway. Disallow
it.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
---

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 957fb70..c577bae 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -3638,6 +3638,12 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev,
 		goto out;
 	}
 
+	if (crtc->fb->pixel_format != fb->pixel_format) {
+		DRM_DEBUG_KMS("Page flip is not allowed to change frame buffer format.\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
 	if (page_flip->flags & DRM_MODE_PAGE_FLIP_EVENT) {
 		ret = -ENOMEM;
 		spin_lock_irqsave(&dev->event_lock, flags);