Re: [PATCH 18/25] drm/msm/dpu: merge RM interface reservation helpers

[Jordan Crouse <jcrouse-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>]

On Mon, Oct 08, 2018 at 09:27:35PM -0700, Jeykumar Sankaran wrote:
> we don't have enough reasons why the HW block looping's
> cannot happen in the same function. So merge them.

looping's -> looping. So there are reasons one might break them out
but not interesting ones?

> Signed-off-by: Jeykumar Sankaran <jsanka@codeaurora.org>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c | 63 ++++++++++++++--------------------
>  1 file changed, 26 insertions(+), 37 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
> index a79456c..bb59250 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c
> @@ -435,52 +435,39 @@ static int _dpu_rm_reserve_ctls(
>  	return 0;
>  }
>  
> -static struct dpu_rm_hw_blk *_dpu_rm_reserve_intf(
> -		struct dpu_rm *rm,
> -		uint32_t id,
> -		enum dpu_hw_blk_type type)
> -{
> -	struct dpu_rm_hw_blk *iter;
> -	struct list_head *blk_list = &rm->hw_blks[DPU_HW_BLK_INTF];
> -
> -	/* Find the block entry in the rm, and note the reservation */
> -	list_for_each_entry(iter, blk_list, list)  {
> -		if (iter->hw->id != id || iter->in_use)
> -			continue;
> -
> -		trace_dpu_rm_reserve_intf(iter->hw->id, DPU_HW_BLK_INTF);
> -
> -		break;
> -	}
> -
> -	/* Shouldn't happen since intfs are fixed at probe */
> -	if (!iter) {
> -		DPU_ERROR("couldn't find type %d id %d\n", type, id);
> -		return NULL;
> -	}
> -
> -	return iter;
> -}
> -
> -static int _dpu_rm_reserve_intf_related_hw(
> +static int _dpu_rm_reserve_intfs(
>  		struct dpu_rm *rm,
>  		struct dpu_crtc_state *dpu_cstate,
>  		struct dpu_encoder_hw_resources *hw_res)
>  {
> -	struct dpu_rm_hw_blk *blk;
> +	struct dpu_rm_hw_blk *iter;
> +	struct list_head *blk_list = &rm->hw_blks[DPU_HW_BLK_INTF];
>  	int i, num_intfs = 0;
>  
>  	for (i = 0; i < ARRAY_SIZE(hw_res->intfs); i++) {
> +		struct dpu_rm_hw_blk *intf_blk = NULL;
> +
>  		if (hw_res->intfs[i] == INTF_MODE_NONE)
>  			continue;
>  
> -		blk = _dpu_rm_reserve_intf(rm, i + INTF_0,
> -				DPU_HW_BLK_INTF);
> -		if (!blk)
> -			return -ENAVAIL;
> +		list_for_each_entry(iter, blk_list, list)  {
> +			if (iter->in_use)
> +				continue;
> +
> +			if (iter->hw->id == (INTF_0 + i)) {
> +				intf_blk = iter;
> +				break;
> +			}
> +		}
> +
> +		if (!intf_blk)
> +			return -EINVAL;
>  
> -		blk->in_use = true;
> -		dpu_cstate->hw_intfs[num_intfs++] = to_dpu_hw_intf(blk->hw);
> +		intf_blk->in_use = true;
> +		dpu_cstate->hw_intfs[num_intfs++] =
> +						to_dpu_hw_intf(intf_blk->hw);
> +
> +		trace_dpu_rm_reserve_intf(intf_blk->hw->id, DPU_HW_BLK_INTF);
>  	}
>  
>  	dpu_cstate->num_intfs = num_intfs;
> @@ -507,9 +494,11 @@ static int _dpu_rm_make_reservation(
>  		return ret;
>  	}
>  
> -	ret = _dpu_rm_reserve_intf_related_hw(rm, dpu_cstate, &reqs->hw_res);
> -	if (ret)
> +	ret = _dpu_rm_reserve_intfs(rm, dpu_cstate, &reqs->hw_res);
> +	if (ret) {
> +		DPU_ERROR("unable to find appropriate INTF\n");

Since there is only once consumer of this function, I would move this error
message down into the sub-function and provide more debug information - like
which INTF wasn't found.

>  		return ret;
> +	}

And you don't need to return ret in this block - you can just drop out to the
bottom.

>  
>  	return ret;
>  }

-- 
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
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