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

Jordan Crouse
2018-10-09T16:50:22Z

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;
> }

--
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