From 2cade218d6eb8f50792cc7c247de15d324242f20 Mon Sep 17 00:00:00 2001
From: sunliming <sunliming@kylinos.cn>
Date: Thu, 23 Jun 2022 09:27:07 +0800
Subject: drm/msm/dpu: Fix variable dereferenced before check
Git-commit: eb174bd875ae504cdc1b5b209da288fffb1e5128
Patch-mainline: v5.19-rc5
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

Fixes the following smatch warning:

drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c:261
dpu_encoder_phys_wb_atomic_check() warn: variable dereferenced before check 'conn_state'

Fixes: d7d0e73f7de3 ("drm/msm/dpu: introduce the dpu_encoder_phys_* for writeback")
Signed-off-by: sunliming <sunliming@kylinos.cn>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/490850/
Link: https://lore.kernel.org/r/20220623012707.453972-1-sunliming@kylinos.cn
Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
index 59da348ff339..0ec809ab06e7 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c
@@ -252,11 +252,6 @@ static int dpu_encoder_phys_wb_atomic_check(
 	DPU_DEBUG("[atomic_check:%d, \"%s\",%d,%d]\n",
 			phys_enc->wb_idx, mode->name, mode->hdisplay, mode->vdisplay);
 
-	if (!conn_state->writeback_job || !conn_state->writeback_job->fb)
-		return 0;
-
-	fb = conn_state->writeback_job->fb;
-
 	if (!conn_state || !conn_state->connector) {
 		DPU_ERROR("invalid connector state\n");
 		return -EINVAL;
@@ -267,6 +262,11 @@ static int dpu_encoder_phys_wb_atomic_check(
 		return -EINVAL;
 	}
 
+	if (!conn_state->writeback_job || !conn_state->writeback_job->fb)
+		return 0;
+
+	fb = conn_state->writeback_job->fb;
+
 	DPU_DEBUG("[fb_id:%u][fb:%u,%u]\n", fb->base.id,
 			fb->width, fb->height);
 
-- 
2.38.1