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From:   Haowen Bai <baihaowen@meizu.com>
To:     Rob Clark <robdclark@gmail.com>,
        Abhinav Kumar <quic_abhinavk@quicinc.com>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Sean Paul <sean@poorly.run>, David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>
CC:     Haowen Bai <baihaowen@meizu.com>, <linux-arm-msm@vger.kernel.org>,
        <dri-devel@lists.freedesktop.org>,
        <freedreno@lists.freedesktop.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH] drm/msm/dpu: Fix pointer dereferenced before checking
Date:   Mon, 30 May 2022 15:33:24 +0800
Message-ID: <1653896005-25168-1-git-send-email-baihaowen@meizu.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

The ctx->hw is dereferencing before null checking, so move
it after checking.

Signed-off-by: Haowen Bai <baihaowen@meizu.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_hw_wb.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_wb.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_wb.c
index bcccce292937..e59680cdd0ce 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_wb.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_wb.c
@@ -155,11 +155,13 @@ static void dpu_hw_wb_roi(struct dpu_hw_wb *ctx, struct dpu_hw_wb_cfg *wb)
 static void dpu_hw_wb_setup_qos_lut(struct dpu_hw_wb *ctx,
 		struct dpu_hw_wb_qos_cfg *cfg)
 {
-	struct dpu_hw_blk_reg_map *c = &ctx->hw;
+	struct dpu_hw_blk_reg_map *c;
 	u32 qos_ctrl = 0;
 
 	if (!ctx || !cfg)
 		return;
+	
+	c = &ctx->hw;
 
 	DPU_REG_WRITE(c, WB_DANGER_LUT, cfg->danger_lut);
 	DPU_REG_WRITE(c, WB_SAFE_LUT, cfg->safe_lut);
-- 
2.7.4