MLK-18031 video: mxsfb: enable global alpha when grayscale is 0 for 32bpp format

For overlay framebuffer, when its grayscale is '0' and the format
bpp is 32, enable the global alpha blending by default which can
make the overlay fb can display the framebuffer content as long as
it is unblanked.

Signed-off-by: Fancy Fang <chen.fang@nxp.com>
(cherry picked from commit fede70b9066b03c24347619775fd7d007c5ddafb)

diff --git a/drivers/video/fbdev/mxsfb.c b/drivers/video/fbdev/mxsfb.c
index 98cd5e3..5659ec2 100644 (file)
--- a/drivers/video/fbdev/mxsfb.c
+++ b/drivers/video/fbdev/mxsfb.c
@@ -1666,6 +1666,7 @@ static void overlayfb_setup(struct mxsfb_layer *ofb)
                        break;
                case 32: /* ARGB8888 */
                        format = 0x0;
+                       global_alpha_en = 1;
                        break;
                default:
                        return;