Re: [PATCH 1/2] drm/msm/dpu: drop SSPP register dumpers

[Abhinav Kumar <quic_abhinavk@quicinc.com>]

On 5/21/2023 10:21 AM, Dmitry Baryshkov wrote:
> Drop SSPP-specifig debugfs register dumps in favour of using
> debugfs/dri/0/kms or devcoredump.
> 

I did see another series which removes src_blk from the catalog (I am 
yet to review that one) . Lets assume that one is fine and this change 
will be going on top of that one right?

The concern I have with this change is that although I do agree that we 
should be in favor of using debugfs/dri/0/kms ( i have used it a few 
times and it works pretty well ), devcoredump does not have the support 
to dump sub-blocks . Something which we should add with priority because 
even with DSC blocks with the separation of enc/ctl blocks we need that 
like I wrote in one of the responses.

So the "len" of the blocks having sub-blocks will be ignored in favor of 
the len of the sub-blocks.

If we remove this without adding that support first, its a loss of debug 
functionality.

Can we retain these blocks and remove dpu_debugfs_create_regset32 in a 
different way?


> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_sspp.c | 25 ---------------------
>   1 file changed, 25 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_sspp.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_sspp.c
> index bfd82c2921af..6c5ebee2f7cd 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_sspp.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_sspp.c
> @@ -727,31 +727,6 @@ int _dpu_hw_sspp_init_debugfs(struct dpu_hw_sspp *hw_pipe, struct dpu_kms *kms,
>   	debugfs_create_xul("features", 0600,
>   			debugfs_root, (unsigned long *)&hw_pipe->cap->features);
>   
> -	/* add register dump support */
> -	dpu_debugfs_create_regset32("src_blk", 0400,
> -			debugfs_root,
> -			sblk->src_blk.base + cfg->base,
> -			sblk->src_blk.len,
> -			kms);
> -
> -	if (cfg->features & BIT(DPU_SSPP_SCALER_QSEED3) ||
> -			cfg->features & BIT(DPU_SSPP_SCALER_QSEED3LITE) ||
> -			cfg->features & BIT(DPU_SSPP_SCALER_QSEED2) ||
> -			cfg->features & BIT(DPU_SSPP_SCALER_QSEED4))
> -		dpu_debugfs_create_regset32("scaler_blk", 0400,
> -				debugfs_root,
> -				sblk->scaler_blk.base + cfg->base,
> -				sblk->scaler_blk.len,
> -				kms);
> -
> -	if (cfg->features & BIT(DPU_SSPP_CSC) ||
> -			cfg->features & BIT(DPU_SSPP_CSC_10BIT))
> -		dpu_debugfs_create_regset32("csc_blk", 0400,
> -				debugfs_root,
> -				sblk->csc_blk.base + cfg->base,
> -				sblk->csc_blk.len,
> -				kms);
> -
>   	debugfs_create_u32("xin_id",
>   			0400,
>   			debugfs_root,