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Message-ID: <1530871434.15725.10.camel@pengutronix.de>
Subject: Re: [PATCH 1/4] drm/v3d: Delay the scheduler timeout if we're still
 making progress.
From:   Lucas Stach <l.stach@pengutronix.de>
To:     Eric Anholt <eric@anholt.net>, dri-devel@lists.freedesktop.org
Cc:     linux-kernel@vger.kernel.org
Date:   Fri, 06 Jul 2018 12:03:54 +0200
In-Reply-To: <20180703170515.6298-1-eric@anholt.net>
References: <20180703170515.6298-1-eric@anholt.net>
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Am Dienstag, den 03.07.2018, 10:05 -0700 schrieb Eric Anholt:
> GTF-GLES2.gtf.GL.acos.acos_float_vert_xvary submits jobs that take 4
> seconds at maximum resolution, but we still want to reset quickly if a
> job is really hung.  Sample the CL's current address and the return
> address (since we call into tile lists repeatedly) and if either has
> changed then assume we've made progress.
> 
> > Signed-off-by: Eric Anholt <eric@anholt.net>
> Cc: Lucas Stach <l.stach@pengutronix.de>

Reviewed-by: Lucas Stach <l.stach@pengutronix.de>

> ---
>  drivers/gpu/drm/v3d/v3d_drv.h   |  2 ++
>  drivers/gpu/drm/v3d/v3d_regs.h  |  1 +
>  drivers/gpu/drm/v3d/v3d_sched.c | 18 ++++++++++++++++++
>  3 files changed, 21 insertions(+)
> 
> diff --git a/drivers/gpu/drm/v3d/v3d_drv.h b/drivers/gpu/drm/v3d/v3d_drv.h
> index f546e0ab9562..a5d96d823416 100644
> --- a/drivers/gpu/drm/v3d/v3d_drv.h
> +++ b/drivers/gpu/drm/v3d/v3d_drv.h
> @@ -189,6 +189,8 @@ struct v3d_job {
>  
> >  	/* GPU virtual addresses of the start/end of the CL job. */
> >  	u32 start, end;
> +
> > +	u32 timedout_ctca, timedout_ctra;
>  };
>  
>  struct v3d_exec_info {
> diff --git a/drivers/gpu/drm/v3d/v3d_regs.h b/drivers/gpu/drm/v3d/v3d_regs.h
> index fc13282dfc2f..854046565989 100644
> --- a/drivers/gpu/drm/v3d/v3d_regs.h
> +++ b/drivers/gpu/drm/v3d/v3d_regs.h
> @@ -222,6 +222,7 @@
>  #define V3D_CLE_CTNCA(n) (V3D_CLE_CT0CA + 4 * n)
>  #define V3D_CLE_CT0RA                                  0x00118
>  #define V3D_CLE_CT1RA                                  0x0011c
> +#define V3D_CLE_CTNRA(n) (V3D_CLE_CT0RA + 4 * n)
>  #define V3D_CLE_CT0LC                                  0x00120
>  #define V3D_CLE_CT1LC                                  0x00124
>  #define V3D_CLE_CT0PC                                  0x00128
> diff --git a/drivers/gpu/drm/v3d/v3d_sched.c b/drivers/gpu/drm/v3d/v3d_sched.c
> index 808bc901f567..00667c733dca 100644
> --- a/drivers/gpu/drm/v3d/v3d_sched.c
> +++ b/drivers/gpu/drm/v3d/v3d_sched.c
> @@ -153,7 +153,25 @@ v3d_job_timedout(struct drm_sched_job *sched_job)
> >  	struct v3d_job *job = to_v3d_job(sched_job);
> >  	struct v3d_exec_info *exec = job->exec;
> >  	struct v3d_dev *v3d = exec->v3d;
> > +	enum v3d_queue job_q = job == &exec->bin ? V3D_BIN : V3D_RENDER;
> >  	enum v3d_queue q;
> > +	u32 ctca = V3D_CORE_READ(0, V3D_CLE_CTNCA(job_q));
> > +	u32 ctra = V3D_CORE_READ(0, V3D_CLE_CTNRA(job_q));
> +
> > +	/* If the current address or return address have changed, then
> > +	 * the GPU has probably made progress and we should delay the
> > +	 * reset.  This could fail if the GPU got in an infinite loop
> > +	 * in the CL, but that is pretty unlikely outside of an i-g-t
> > +	 * testcase.
> > +	 */
> > +	if (job->timedout_ctca != ctca || job->timedout_ctra != ctra) {
> > +		job->timedout_ctca = ctca;
> > +		job->timedout_ctra = ctra;
> +
> > +		schedule_delayed_work(&job->base.work_tdr,
> > +				      job->base.sched->timeout);
> > +		return;
> > +	}
>  
> >  	mutex_lock(&v3d->reset_lock);
>