drm/mediatek: Check if fb is null
[ Upstream commit b1d685b6467ac0d98fc63989f71b4ca9186be5d4 ]
It's possible that state->base.fb is null. Add a check before access its
format.
Fixes: b6b1bb980ec4 ("drm/mediatek: Turn off Alpha bit when plane format has no alpha")
Signed-off-by: Yongqiang Niu <yongqiang.niu@mediatek.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
index 28651bc..faff411 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
@@ -266,7 +266,7 @@ static void mtk_ovl_layer_config(struct mtk_ddp_comp *comp, unsigned int idx,
}
con = ovl_fmt_convert(ovl, fmt);
- if (state->base.fb->format->has_alpha)
+ if (state->base.fb && state->base.fb->format->has_alpha)
con |= OVL_CON_AEN | OVL_CON_ALPHA;
if (pending->rotation & DRM_MODE_REFLECT_Y) {