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

[abhinavk]

On 2020-11-18 12:03, abhinavk@xxxxxxxxxxxxxx wrote:
> Hi Stephen
>
> On 2020-11-18 07:49, Rob Clark wrote:
> > On Tue, Nov 17, 2020 at 2:53 PM Stephen Boyd <swboyd@xxxxxxxxxxxx> 
> > wrote:
> > > Quoting abhinavk@xxxxxxxxxxxxxx (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@xxxxxxxxxx>
> > > > > Cc: Abhinav Kumar <abhinavk@xxxxxxxxxxxxxx>
> > > > > Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
> > > >
> > > > > ---
> > > > >  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 : 
https://patchwork.freedesktop.org/patch/401929/