drm/meson: Correct OSD1 global alpha value

[ Upstream commit 6836829c8ea453c9e3e518e61539e35881c8ed5f ]

VIU_OSD1_CTRL_STAT.GLOBAL_ALPHA is a 9 bit field, so the maximum
value is 0x100 not 0xff.

This matches the vendor kernel.

Signed-off-by: Stuart Menefy <stuart.menefy@mathembedded.com>
Fixes: bbbe775ec5b5 ("drm: Add support for Amlogic Meson Graphic Controller")
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220908155103.686904-1-stuart.menefy@mathembedded.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/meson/meson_plane.c b/drivers/gpu/drm/meson/meson_plane.c
index 35338ed1820996383ee1ef8afa717b004aa4e3f9..255c6b863f8d2cdebe514ec4d85c86f6c85f92ec 100644 (file)
--- a/drivers/gpu/drm/meson/meson_plane.c
+++ b/drivers/gpu/drm/meson/meson_plane.c
@@ -163,7 +163,7 @@ static void meson_plane_atomic_update(struct drm_plane *plane,
 
        /* Enable OSD and BLK0, set max global alpha */
        priv->viu.osd1_ctrl_stat = OSD_ENABLE |
-                                  (0xFF << OSD_GLOBAL_ALPHA_SHIFT) |
+                                  (0x100 << OSD_GLOBAL_ALPHA_SHIFT) |
                                   OSD_BLK0_ENABLE;
 
        priv->viu.osd1_ctrl_stat2 = readl(priv->io_base +