[PATCH v3 3/5] drm/msm/dpu: handle perf mode in _dpu_core_perf_crtc_update_bus()

[Abhinav Kumar]

On 3/19/2024 1:43 PM, Dmitry Baryshkov wrote:
> On Tue, 19 Mar 2024 at 22:34, Abhinav Kumar <quic_abhinavk at quicinc.com> wrote:
>>
>>
>>
>> On 3/13/2024 6:10 PM, Dmitry Baryshkov wrote:
>>> Move perf mode handling for the bandwidth to
>>> _dpu_core_perf_crtc_update_bus() rather than overriding per-CRTC data
>>> and then aggregating known values.
>>>
>>> Note, this changes the fix_core_ab_vote. Previously it would be
>>> multiplied per the CRTC number, now it will be used directly for
>>> interconnect voting.
>>>
>>> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
>>> ---
>>>    drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c | 39 +++++++++++++--------------
>>>    1 file changed, 19 insertions(+), 20 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c
>>> index 87b892069526..ff2942a6a678 100644
>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c
>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c
>>> @@ -118,21 +118,9 @@ static void _dpu_core_perf_calc_crtc(const struct dpu_core_perf *core_perf,
>>>                return;
>>>        }
>>>
>>> -     memset(perf, 0, sizeof(struct dpu_core_perf_params));
>>> -
>>> -     if (core_perf->perf_tune.mode == DPU_PERF_MODE_MINIMUM) {
>>> -             perf->bw_ctl = 0;
>>> -             perf->max_per_pipe_ib = 0;
>>> -             perf->core_clk_rate = 0;
>>> -     } else if (core_perf->perf_tune.mode == DPU_PERF_MODE_FIXED) {
>>> -             perf->bw_ctl = core_perf->fix_core_ab_vote;
>>> -             perf->max_per_pipe_ib = core_perf->fix_core_ib_vote;
>>> -             perf->core_clk_rate = core_perf->fix_core_clk_rate;
>>> -     } else {
>>> -             perf->bw_ctl = _dpu_core_perf_calc_bw(perf_cfg, crtc);
>>> -             perf->max_per_pipe_ib = perf_cfg->min_dram_ib;
>>> -             perf->core_clk_rate = _dpu_core_perf_calc_clk(perf_cfg, crtc, state);
>>> -     }
>>> +     perf->bw_ctl = _dpu_core_perf_calc_bw(perf_cfg, crtc);
>>> +     perf->max_per_pipe_ib = perf_cfg->min_dram_ib;
>>> +     perf->core_clk_rate = _dpu_core_perf_calc_clk(perf_cfg, crtc, state);
>>>
>>>        DRM_DEBUG_ATOMIC(
>>>                "crtc=%d clk_rate=%llu core_ib=%llu core_ab=%llu\n",
>>> @@ -233,18 +221,29 @@ static int _dpu_core_perf_crtc_update_bus(struct dpu_kms *kms,
>>>    {
>>>        struct dpu_core_perf_params perf = { 0 };
>>>        int i, ret = 0;
>>> -     u64 avg_bw;
>>> +     u32 avg_bw;
>>> +     u32 peak_bw;

Why were avg_bw and peak_bw values brought down to u32?

I think we might go higher so u64 was better.

>>>
>>>        if (!kms->num_paths)
>>>                return 0;
>>>
>>> -     dpu_core_perf_aggregate(crtc->dev, dpu_crtc_get_client_type(crtc), &perf);
>>> +     if (kms->perf.perf_tune.mode == DPU_PERF_MODE_MINIMUM) {
>>> +             avg_bw = 0;
>>> +             peak_bw = 0;
>>> +     } else if (kms->perf.perf_tune.mode == DPU_PERF_MODE_FIXED) {
>>> +             avg_bw = kms->perf.fix_core_ab_vote;
>>> +             peak_bw = kms->perf.fix_core_ib_vote;

Instead of changing the value of avg_bw like mentioned in commit text, 
why cant we do avg_bw = fix_core_ab * (drm_mode_config::num_crtc);

Any reason you want to change it from "per CRTC fixed" to just "fixed"?

Now, the user who wants to hard-code this also needs to first account 
for number of CRTCs from the dri state and then program the fixed value 
using debugfs. Thats not convenient.

>>> +     } else {
>>> +             dpu_core_perf_aggregate(crtc->dev, dpu_crtc_get_client_type(crtc), &perf);
>>
>> Where is this function dpu_core_perf_aggregate() defined? I dont see it
>> in msm-next
> 
> In the previous patch.
> 

Sorry, my bad. I thought it had a different name in the prev patch :/


>>
>>> +
>>> +             avg_bw = div_u64(perf.bw_ctl, 1000); /*Bps_to_icc*/
>>> +             peak_bw = perf.max_per_pipe_ib;
>>> +     }
>>>
>>> -     avg_bw = perf.bw_ctl;
>>> -     do_div(avg_bw, (kms->num_paths * 1000)); /*Bps_to_icc*/
>>> +     avg_bw /= kms->num_paths;
>>>

>>>        for (i = 0; i < kms->num_paths; i++)
>>> -             icc_set_bw(kms->path[i], avg_bw, perf.max_per_pipe_ib);
>>> +             icc_set_bw(kms->path[i], avg_bw, peak_bw);
>>>
>>>        return ret;
>>>    }
>>>
> 
> 
>