diff mbox series

[resend] drm/armada: Fix off-by-one error in armada_overlay_get_property()

Message ID 788e97ac9b2aeee1941f274bf7b279b68c7592b6.1669045360.git.geert+renesas@glider.be
State New
Headers
Series [resend] drm/armada: Fix off-by-one error in armada_overlay_get_property() |

Commit Message

Geert Uytterhoeven Nov. 21, 2022, 3:43 p.m. UTC 
  As ffs() returns one more than the index of the first bit set (zero
means no bits set), the color key mode value is shifted one position too
much.

Fix this by using FIELD_GET() instead.

Fixes: c96103b6c49ff9a8 ("drm/armada: move colorkey properties into overlay plane state")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
Compile-tested only.
---
 drivers/gpu/drm/armada/armada_overlay.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Comments

Russell King (Oracle) Nov. 21, 2022, 3:54 p.m. UTC | #1 
On Mon, Nov 21, 2022 at 04:43:14PM +0100, Geert Uytterhoeven wrote:
> As ffs() returns one more than the index of the first bit set (zero
> means no bits set), the color key mode value is shifted one position too
> much.
> 
> Fix this by using FIELD_GET() instead.

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/armada/armada_overlay.c b/drivers/gpu/drm/armada/armada_overlay.c
index f21eb8fb76d87285..3b9bd8ecda137f6d 100644
--- a/drivers/gpu/drm/armada/armada_overlay.c
+++ b/drivers/gpu/drm/armada/armada_overlay.c
@@ -4,6 +4,8 @@ 
  *  Rewritten from the dovefb driver, and Armada510 manuals.
  */
 
+#include <linux/bitfield.h>
+
 #include <drm/armada_drm.h>
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
@@ -445,8 +447,8 @@  static int armada_overlay_get_property(struct drm_plane *plane,
 			     drm_to_overlay_state(state)->colorkey_ug,
 			     drm_to_overlay_state(state)->colorkey_vb, 0);
 	} else if (property == priv->colorkey_mode_prop) {
-		*val = (drm_to_overlay_state(state)->colorkey_mode &
-			CFG_CKMODE_MASK) >> ffs(CFG_CKMODE_MASK);
+		*val = FIELD_GET(CFG_CKMODE_MASK,
+				 drm_to_overlay_state(state)->colorkey_mode);
 	} else if (property == priv->brightness_prop) {
 		*val = drm_to_overlay_state(state)->brightness + 256;
 	} else if (property == priv->contrast_prop) {