[PATCH] drm/msm/dpu: don't access mode pointer before it is set

[PATCH] drm/msm/dpu: don't access mode pointer before it is set

[Dmitry Baryshkov]

Move the initializer for the mode variable to the declaration point to
remove unitialized variable access from the DEBUG_DPU macro. This fixes
the following warning:

drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c:250:37: note: initialize the variable 'mode' to silence this warning

Fixes: d7d0e73f7de3 ("drm/msm/dpu: introduce the dpu_encoder_phys_* for writeback")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c | 3 +--
 1 file changed, 1 insertion(+), 2 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 f4a79715a02e..4829d1ce0cf8 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
@@ -247,7 +247,7 @@ static int dpu_encoder_phys_wb_atomic_check(
 		struct drm_connector_state *conn_state)
 {
 	struct drm_framebuffer *fb;
-	const struct drm_display_mode *mode;
+	const struct drm_display_mode *mode = &crtc_state->mode;
 
 	DPU_DEBUG("[atomic_check:%d, \"%s\",%d,%d]\n",
 			phys_enc->wb_idx, mode->name, mode->hdisplay, mode->vdisplay);
@@ -256,7 +256,6 @@ static int dpu_encoder_phys_wb_atomic_check(
 		return 0;
 
 	fb = conn_state->writeback_job->fb;
-	mode = &crtc_state->mode;
 
 	if (!conn_state || !conn_state->connector) {
 		DPU_ERROR("invalid connector state\n");
-- 
2.35.1

Re: [PATCH] drm/msm/dpu: don't access mode pointer before it is set

[Abhinav Kumar]

On 5/2/2022 1:24 AM, Dmitry Baryshkov wrote:
> Move the initializer for the mode variable to the declaration point to
> remove unitialized variable access from the DEBUG_DPU macro. This fixes
> the following warning:
> 
> drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c:250:37: note: initialize the variable 'mode' to silence this warning
> 
> Fixes: d7d0e73f7de3 ("drm/msm/dpu: introduce the dpu_encoder_phys_* for writeback")
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Thanks,
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c | 3 +--
>   1 file changed, 1 insertion(+), 2 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 f4a79715a02e..4829d1ce0cf8 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
> @@ -247,7 +247,7 @@ static int dpu_encoder_phys_wb_atomic_check(
>   		struct drm_connector_state *conn_state)
>   {
>   	struct drm_framebuffer *fb;
> -	const struct drm_display_mode *mode;
> +	const struct drm_display_mode *mode = &crtc_state->mode;
>   
>   	DPU_DEBUG("[atomic_check:%d, \"%s\",%d,%d]\n",
>   			phys_enc->wb_idx, mode->name, mode->hdisplay, mode->vdisplay);
> @@ -256,7 +256,6 @@ static int dpu_encoder_phys_wb_atomic_check(
>   		return 0;
>   
>   	fb = conn_state->writeback_job->fb;
> -	mode = &crtc_state->mode;
>   
>   	if (!conn_state || !conn_state->connector) {
>   		DPU_ERROR("invalid connector state\n");