Re: [Freedreno] [PATCH] drm/msm/dpu: Remove chatty vbif debug print

abhinavk
2020-11-19T21:44:35Z

On 2020-11-18 12:03, abhinavk@codeaurora.org wrote:
> Hi Stephen
>
> On 2020-11-18 07:49, Rob Clark wrote:
>> On Tue, Nov 17, 2020 at 2:53 PM Stephen Boyd <swboyd@chromium.org>
>> wrote:
>>>
>>> Quoting abhinavk@codeaurora.org (2020-11-17 12:34:56)
>>> > On 2020-11-17 09:26, Stephen Boyd wrote:
>>> > > I don't know what this debug print is for but it is super chatty,
>>> > > throwing 8 lines of debug prints in the logs every time we update a
>>> > > plane. It looks like it has no value. Let's nuke it so we can get
>>> > > better logs.
>>> > >
>>> > > Cc: Sean Paul <sean@poorly.run>
>>> > > Cc: Abhinav Kumar <abhinavk@codeaurora.org>
>>> > > Signed-off-by: Stephen Boyd <swboyd@chromium.org>
>>> >
>>> > > ---
>>> > > drivers/gpu/drm/msm/disp/dpu1/dpu_vbif.c | 3 ---
>>> > > 1 file changed, 3 deletions(-)
>>> > >
>>> > > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_vbif.c
>>> > > b/drivers/gpu/drm/msm/disp/dpu1/dpu_vbif.c
>>> > > index 5e8c3f3e6625..5eb2b2ee09f5 100644
>>> > > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_vbif.c
>>> > > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_vbif.c
>>> > > @@ -245,9 +245,6 @@ void dpu_vbif_set_qos_remap(struct dpu_kms
>>> > > *dpu_kms,
>>> > > forced_on = mdp->ops.setup_clk_force_ctrl(mdp, params->clk_ctrl,
>>> > > true);
>>> > >
>>> > > for (i = 0; i < qos_tbl->npriority_lvl; i++) {
>>> > > - DPU_DEBUG("vbif:%d xin:%d lvl:%d/%d\n",
>>> > > - params->vbif_idx, params->xin_id, i,
>>> > > - qos_tbl->priority_lvl[i]);
>>> >
>>> > Instead of getting rid of this print, we should optimize the caller of
>>> > this.
>>>
>>> Does the print tell us anything? Right now it prints 8 lines where it
>>> feels like it could be trimmed down:
>>>
>>> [drm:dpu_vbif_set_qos_remap] vbif:0 xin:0 lvl:0/3
>>> [drm:dpu_vbif_set_qos_remap] vbif:0 xin:0 lvl:1/3
>>> [drm:dpu_vbif_set_qos_remap] vbif:0 xin:0 lvl:2/4
>>> [drm:dpu_vbif_set_qos_remap] vbif:0 xin:0 lvl:3/4
>>> [drm:dpu_vbif_set_qos_remap] vbif:0 xin:0 lvl:4/5
>>> [drm:dpu_vbif_set_qos_remap] vbif:0 xin:0 lvl:5/5
>>> [drm:dpu_vbif_set_qos_remap] vbif:0 xin:0 lvl:6/6
>>> [drm:dpu_vbif_set_qos_remap] vbif:0 xin:0 lvl:7/6
>>>
>>> maybe one line that combines the index into values?
>>>
>>> [drm:dpu_vbif_set_qos_remap] vbif:0 xin:0 [3 3 4 4 5 5 6
>>> 6]
>>>
>>
>> or possibly convert to a tracepoint (so it doesn't spam the drm_trace
>> buffer)
>>
>> BR,
>> -R
>>
>>> But again I have no idea if this print is really useful. Maybe we can
>>> print it only if the value changes from what was already there?
>>> Basically move the print into dpu_hw_set_qos_remap() and then skip
>>> out
>>> early if nothing changed or print and modify the register.
>>>
>>> > This is what
>>> > we are doing in downstream. So we need to update the property only if we
>>> > are switching from a RT client
>>> > to non-RT client for the plane and vice-versa. So we should try to do
>>> > the same thing here.
>>> >
>>> > is_rt = sde_crtc_is_rt_client(crtc, crtc->state);
>>> > if (is_rt != psde->is_rt_pipe) {
>>> > psde->is_rt_pipe = is_rt;
>>> > pstate->dirty |= SDE_PLANE_DIRTY_QOS;
>>> > }
>>> >
>>> >
>>> > if (pstate->dirty & DPU_PLANE_DIRTY_QOS)
>>> > _dpu_plane_set_qos_remap(plane);
>>> >
>>>
>>> Sounds great! Can you send the patch?
>
> Will finalize approach and send the patch in a day or two.
>
> Thanks
>
> Abhinav

patch has been posted here for review :