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From:   Yongqiang Niu <yongqiang.niu@mediatek.com>
To:     CK Hu <ck.hu@mediatek.com>, Philipp Zabel <p.zabel@pengutronix.de>,
        Rob Herring <robh+dt@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>
CC:     David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
        Mark Rutland <mark.rutland@arm.com>,
        <dri-devel@lists.freedesktop.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-mediatek@lists.infradead.org>,
        <Project_Global_Chrome_Upstream_Group@mediatek.com>,
        Hsin-Yi Wang <hsinyi@chromium.org>,
        Yongqiang Niu <yongqiang.niu@mediatek.com>
Subject: [PATCH v3, 08/15] drm/mediatek: check if fb is null
Date:   Mon, 11 Jan 2021 15:43:44 +0800
Message-ID: <1610351031-21133-9-git-send-email-yongqiang.niu@mediatek.com>
In-Reply-To: <1610351031-21133-1-git-send-email-yongqiang.niu@mediatek.com>
References: <1610351031-21133-1-git-send-email-yongqiang.niu@mediatek.com>
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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>
---
 drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
index 4934bee..8e7f494 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c
@@ -279,7 +279,7 @@ 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) {
-- 
1.8.1.1.dirty