Re: [PATCH 6/6] drm/msm/dpu: Update dev core dump to dump registers of sub blocks

[Dmitry Baryshkov]

On 23/06/2023 02:48, Ryan McCann wrote:
> Currently, the device core dump mechanism does not dump registers of sub
> blocks within the DSPP, SSPP, DSC, and PINGPONG blocks. Add wrapper
> function to dump hardware blocks that contain sub blocks.
>
> Signed-off-by: Ryan McCann <quic_rmccann@xxxxxxxxxxx>
> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 194 +++++++++++++++++++++++++++-----
>   1 file changed, 168 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> index aa8499de1b9f..9b1b1c382269 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> @@ -885,6 +885,154 @@ static int dpu_irq_postinstall(struct msm_kms *kms)
>   	return 0;
>   }
>   
> +static void dpu_kms_mdp_snapshot_add_block(struct msm_disp_state *disp_state,
> +					   void __iomem *mmio, void *blk,
> +					   enum dpu_hw_blk_type blk_type)
> +{
> +	u32 base;
> +
> +	switch (blk_type) {
> +	case DPU_HW_BLK_TOP:
> +	{
> +		struct dpu_mdp_cfg *top = (struct dpu_mdp_cfg *)blk;

Block configuration is constant, so these should be constant pointers. 
Not to mention that such type conversions are usually considered to be a 
bad idea. We loose type information, so compiler can not catch any 
errors here.

> +
> +		if (top->features & BIT(DPU_MDP_PERIPH_0_REMOVED)) {
> +			msm_disp_snapshot_add_block(disp_state, MDP_PERIPH_TOP0,
> +						    mmio + top->base, "top");
> +			msm_disp_snapshot_add_block(disp_state, top->len - MDP_PERIPH_TOP0_END,
> +						    mmio + top->base + MDP_PERIPH_TOP0_END,
> +						    "top_2");
> +		} else {
> +			msm_disp_snapshot_add_block(disp_state, top->len, mmio + top->base, "top");
> +		}
> +		break;

[skipped]

	default:
> +		DPU_ERROR("Block type not supported.");

Which block type?

> +	}
> +}
> +
>   static void dpu_kms_mdp_snapshot(struct msm_disp_state *disp_state, struct msm_kms *kms)
>   {
>   	int i;
> @@ -899,53 +1047,47 @@ static void dpu_kms_mdp_snapshot(struct msm_disp_state *disp_state, struct msm_k
>   
>   	/* dump CTL sub-blocks HW regs info */
>   	for (i = 0; i < cat->ctl_count; i++)
> -		msm_disp_snapshot_add_block(disp_state, cat->ctl[i].len,
> -				dpu_kms->mmio + cat->ctl[i].base, "ctl_%d", i);
> +		dpu_kms_mdp_snapshot_add_block(disp_state, dpu_kms->mmio, (void *)&cat->ctl[i],

Here we are loosing the const property, which is a bad idea.

> +					       DPU_HW_BLK_CTL);

--
With best wishes
Dmitry