Re: [PATCH] drm/msm/dpu: Bind pingpong block to intf on active ctls in cmd encoder

[Dmitry Baryshkov]

On 02/02/2022 12:48, Marijn Suijten wrote:
> On 2022-01-20 02:12:51, Dmitry Baryshkov wrote:
> > On 22/12/2021 13:55, Marijn Suijten wrote:
> > > As per the specification of DPU_CTL_ACTIVE_CFG the configuration of
> > > active blocks should be proactively specified, and the pingpong block is
> > > no different.
> > >
> > > The downstream display driver [1] confirms this by also calling
> > > bind_pingpong_blk on CTL_ACTIVE_CFG.  Note that this else-if is always
> > > entered, as setup_intf_cfg - unlike this mainline dpu driver that
> > > combines both behind the same function pointer - is left NULL in favour
> > > of using setup_intf_cfg_v1 when CTL_ACTIVE_CFG is set.
> > >
> > > This solves continuous timeouts on at least the Qualcomm sm6125 SoC:
> > >
> > >       [drm:dpu_encoder_frame_done_timeout:2091] [dpu error]enc31 frame done timeout
> > >       [drm:_dpu_encoder_phys_cmd_handle_ppdone_timeout.isra.0] *ERROR* id:31 pp:0 kickoff timeout 0 cnt 1 koff_cnt 1
> > >       [drm:dpu_encoder_phys_cmd_prepare_for_kickoff] *ERROR* failed wait_for_idle: id:31 ret:-110 pp:0
> > >
> > > In the same way this pingpong block should also be unbound followed by
> > > an interface flush when the encoder is disabled, according to the
> > > downstream display driver [2].
> > >
> > > [1]: https://source.codeaurora.org/quic/la/platform/vendor/opensource/display-drivers/tree/msm/sde/sde_encoder_phys_cmd.c?h=LA.UM.9.16.r1-08500-MANNAR.0#n167
> > > [2]: https://source.codeaurora.org/quic/la/platform/vendor/opensource/display-drivers/tree/msm/sde/sde_encoder.c?h=LA.UM.9.16.r1-08500-MANNAR.0#n2986
> > >
> > > Signed-off-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
> > > Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxxx>
> >
> > Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> >
> > > ---
> > >    .../drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c  | 21 +++++++++++++++++++
> > >    1 file changed, 21 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> > > index 8e433af7aea4..e0e08a874f07 100644
> > > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> > > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> > > @@ -71,6 +71,13 @@ static void _dpu_encoder_phys_cmd_update_intf_cfg(
> > >    	intf_cfg.stream_sel = cmd_enc->stream_sel;
> > >    	intf_cfg.mode_3d = dpu_encoder_helper_get_3d_blend_mode(phys_enc);
> > >    	ctl->ops.setup_intf_cfg(ctl, &intf_cfg);
> > > +
> > > +	/* setup which pp blk will connect to this intf */
> > > +	if (test_bit(DPU_CTL_ACTIVE_CFG, &ctl->caps->features) && phys_enc->hw_intf->ops.bind_pingpong_blk)
> >
> > Nit: here we bind all interfaces, but later we unbind only master. Is
> > this correct?
>
> Not sure: it seems downstream only calls
> _sde/dpu_encoder_phys_cmd_update_intf_cfg when it is _not_ a ppsplit
> slave, which appears to be very similar to being the master (both check
> for ENC_ROLE_SLAVE but ppsplit also checks RM topology support for
> ppsplit).  Should we do this too before calling
> _dpu_encoder_phys_cmd_update_intf_cfg?

The PP split is a special topology using a single LM, but two PP (and 
two INTFs). The dpu driver doesn't provide support for it, so ppsplit is 
always false.


> - Marijn
>
> > > +		phys_enc->hw_intf->ops.bind_pingpong_blk(
> > > +				phys_enc->hw_intf,
> > > +				true,
> > > +				phys_enc->hw_pp->idx);
> > >    }
> > >    
> > >    static void dpu_encoder_phys_cmd_pp_tx_done_irq(void *arg, int irq_idx)
> > > @@ -507,6 +514,7 @@ static void dpu_encoder_phys_cmd_disable(struct dpu_encoder_phys *phys_enc)
> > >    {
> > >    	struct dpu_encoder_phys_cmd *cmd_enc =
> > >    		to_dpu_encoder_phys_cmd(phys_enc);
> > > +	struct dpu_hw_ctl *ctl;
> > >    
> > >    	if (!phys_enc->hw_pp) {
> > >    		DPU_ERROR("invalid encoder\n");
> > > @@ -523,6 +531,19 @@ static void dpu_encoder_phys_cmd_disable(struct dpu_encoder_phys *phys_enc)
> > >    
> > >    	if (phys_enc->hw_pp->ops.enable_tearcheck)
> > >    		phys_enc->hw_pp->ops.enable_tearcheck(phys_enc->hw_pp, false);
> > > +
> > > +	if (dpu_encoder_phys_cmd_is_master(phys_enc)) {

Please remove this condition. Just check for existence of bind_pingpong_blk.

> > > +		if (phys_enc->hw_intf->ops.bind_pingpong_blk) {
> > > +			phys_enc->hw_intf->ops.bind_pingpong_blk(
> > > +					phys_enc->hw_intf,
> > > +					false,
> > > +					phys_enc->hw_pp->idx);
> > > +
> > > +			ctl = phys_enc->hw_ctl;
> > > +			ctl->ops.update_pending_flush_intf(ctl, phys_enc->intf_idx);
> > > +		}
> > > +	}
> > > +
> > >    	phys_enc->enable_state = DPU_ENC_DISABLED;
> > >    }
> > >    
> >
> >
> > --
> > With best wishes
> > Dmitry


--
With best wishes
Dmitry