[PATCH v5 02/16] drm/msm/dpu: fix error condition in dpu_encoder_virt_atomic_mode_set

[Abhinav Kumar]

On 6/24/2024 2:13 PM, Dmitry Baryshkov wrote:
> The commit b954fa6baaca ("drm/msm/dpu: Refactor rm iterator") removed
> zero-init of the hw_ctl array, but didn't change the error condition,
> that checked for hw_ctl[i] being NULL. Use indices check instead.
> 
> Fixes: b954fa6baaca ("drm/msm/dpu: Refactor rm iterator")
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> index 5d205e09cf45..7613005fbfea 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> @@ -1186,7 +1186,7 @@ static void dpu_encoder_virt_atomic_mode_set(struct drm_encoder *drm_enc,
>   			return;
>   		}
>   
> -		if (!hw_ctl[i]) {
> +		if (i >= num_ctl) {

This is not very clear to me.

How will we hit this condition? I dont see i going beyond 1 in this loop 
and neither should num_ctl

Will it be just easier to bring back the NULL assignment at the top?

struct dpu_hw_blk *hw_ctl[MAX_CHANNELS_PER_ENC] = { NULL };

I also see the same issue for other blocks such as hw_dsc, hw_lm

>   			DPU_ERROR_ENC(dpu_enc,
>   				"no ctl block assigned at idx: %d\n", i);
>   			return;
>