2024-01-17 19:41:54

by Abhinav Kumar

Subject: [PATCH] drm/msm/dpu: check for valid hw_pp in dpu_encoder_helper_phys_cleanup

The commit 8b45a26f2ba9 ("drm/msm/dpu: reserve cdm blocks for writeback
in case of YUV output") introduced a smatch warning about another
conditional block in dpu_encoder_helper_phys_cleanup() which had assumed
hw_pp will always be valid which may not necessarily be true.

Lets fix the other conditional block by making sure hw_pp is valid
before dereferencing it.

Reported-by: Dan Carpenter <[email protected]>
Fixes: ae4d721ce100 ("drm/msm/dpu: add an API to reset the encoder related hw blocks")
Signed-off-by: Abhinav Kumar <[email protected]>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 83380bc92a00..282d84c872f2 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -2072,7 +2072,7 @@ void dpu_encoder_helper_phys_cleanup(struct dpu_encoder_phys *phys_enc)
}

/* reset the merge 3D HW block */
- if (phys_enc->hw_pp->merge_3d) {
+ if (phys_enc->hw_pp && phys_enc->hw_pp->merge_3d) {
phys_enc->hw_pp->merge_3d->ops.setup_3d_mode(phys_enc->hw_pp->merge_3d,
BLEND_3D_NONE);
if (phys_enc->hw_ctl->ops.update_pending_flush_merge_3d)
@@ -2103,7 +2103,7 @@ void dpu_encoder_helper_phys_cleanup(struct dpu_encoder_phys *phys_enc)
if (phys_enc->hw_wb)
intf_cfg.wb = phys_enc->hw_wb->idx;

- if (phys_enc->hw_pp->merge_3d)
+ if (phys_enc->hw_pp && phys_enc->hw_pp->merge_3d)
intf_cfg.merge_3d = phys_enc->hw_pp->merge_3d->idx;

if (ctl->ops.reset_intf_cfg)
--
2.40.1

2024-01-17 20:50:11

by Dmitry Baryshkov

Subject: Re: [PATCH] drm/msm/dpu: check for valid hw_pp in dpu_encoder_helper_phys_cleanup

On Wed, 17 Jan 2024 at 21:41, Abhinav Kumar <[email protected]> wrote:
>
> The commit 8b45a26f2ba9 ("drm/msm/dpu: reserve cdm blocks for writeback
> in case of YUV output") introduced a smatch warning about another
> conditional block in dpu_encoder_helper_phys_cleanup() which had assumed
> hw_pp will always be valid which may not necessarily be true.
>
> Lets fix the other conditional block by making sure hw_pp is valid
> before dereferencing it.
>
> Reported-by: Dan Carpenter <[email protected]>
> Fixes: ae4d721ce100 ("drm/msm/dpu: add an API to reset the encoder related hw blocks")
> Signed-off-by: Abhinav Kumar <[email protected]>
> ---
> drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)


Reviewed-by: Dmitry Baryshkov <[email protected]>

--
With best wishes
Dmitry