linux-kernel - Re: [PATCH 3/3] media: vsp1: Reset FCP for VSPX

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Message-ID: <20250612175557.GJ330732@ragnatech.se>
Date: Thu, 12 Jun 2025 19:55:57 +0200
From: Niklas Söderlund <niklas.soderlund@...natech.se>
To: Jacopo Mondi <jacopo.mondi@...asonboard.com>
Cc: Laurent Pinchart <laurent.pinchart@...asonboard.com>,
	Jacopo Mondi <jacopo.mondi+renesas@...asonboard.com>,
	Mauro Carvalho Chehab <mchehab@...nel.org>,
	Kieran Bingham <kieran.bingham+renesas@...asonboard.com>,
	linux-media@...r.kernel.org, linux-renesas-soc@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/3] media: vsp1: Reset FCP for VSPX

On 2025-06-12 12:20:13 +0200, Jacopo Mondi wrote:
> Hi Laurent
> 
> On Thu, Jun 12, 2025 at 01:12:15PM +0300, Laurent Pinchart wrote:
> > On Thu, Jun 12, 2025 at 11:48:49AM +0200, Jacopo Mondi wrote:
> > > On Thu, Jun 12, 2025 at 02:36:11AM +0300, Laurent Pinchart wrote:
> > > > On Mon, Jun 09, 2025 at 09:01:44PM +0200, Jacopo Mondi wrote:
> > > > > According section "62.3.7.1 "Operation Control Setting
> > > >
> > > > "According to"
> > > >
> > > > > IP set VSPX+FCPVX" of the R-Car Gen4 Hardware Manual, FCPX has to
> > > > > be reset when stopping the image processing.
> > > >
> > > > That's only when stopping "image process of VSPX+FCPVX immediately".
> > > > Note the "immediately", which involves resetting the VSP too. The code
> > > > below waits for the pipeline to stop at the end of the frame. Resetting
> > > > the FCP doesn't seem to be required in that case.
> > >
> > > True, we certainly don't
> > >
> > > 2. Set value 1 to VSPX register VI6_SRESET.SRST0. VSPX will invoke
> > >    termination process immediately.
> > >
> > > but rather wait for the last frame to complete before stopping the
> > > pipeline.
> > >
> > > Do you think this patch should be dropped ?
> >
> > I would say so, I don't think there's a need to reset the FCP when
> > waiting for the pipeline to stop normally. Or have you noticed issues
> > that this patch would solve ?
> >
> 
> Not really, this comes straight from the upporting of the FCPD reset.
> 
> We've been running with an older of this patch that wasn't actually
> resetting the FCP and we got no issues. At the same time Niklas has
> confirmed running with this version that actually resets the FCP
> doesn't introduce regressions.

I'm not up to snuff on the diff between the two sets. But from our 
discussion on IRC today I dropped all 3 patches from my testing branch 
and that broke my stress tests (after a few runs). I will keep these 
three patches in my ISP branch for now.

Just to be clear the stress tests where fine with the old version too, 
only dropping all 3 reset patches had an negative effect.

> 
> I'm fine dropping this patch indeed
> 
> > > > > Softawre reset the FCPX after the vsp1 pipe has stopped.
> > > >
> > > > s/Softawre/Software/
> > > >
> > > > > Signed-off-by: Jacopo Mondi <jacopo.mondi+renesas@...asonboard.com>
> > > > > ---
> > > > >  drivers/media/platform/renesas/vsp1/vsp1_pipe.c | 7 +++++--
> > > > >  1 file changed, 5 insertions(+), 2 deletions(-)
> > > > >
> > > > > diff --git a/drivers/media/platform/renesas/vsp1/vsp1_pipe.c b/drivers/media/platform/renesas/vsp1/vsp1_pipe.c
> > > > > index a6e5e10f3ef275c1b081c3d957e6cf356332afce..c6f2417aabc479384012ab8ab99556029ede1f44 100644
> > > > > --- a/drivers/media/platform/renesas/vsp1/vsp1_pipe.c
> > > > > +++ b/drivers/media/platform/renesas/vsp1/vsp1_pipe.c
> > > > > @@ -499,6 +499,7 @@ bool vsp1_pipeline_stopped(struct vsp1_pipeline *pipe)
> > > > >  int vsp1_pipeline_stop(struct vsp1_pipeline *pipe)
> > > > >  {
> > > > >  	struct vsp1_device *vsp1 = pipe->output->entity.vsp1;
> > > > > +	u32 version = vsp1->version & VI6_IP_VERSION_MODEL_MASK;
> > > > >  	struct vsp1_entity *entity;
> > > > >  	unsigned long flags;
> > > > >  	int ret;
> > > > > @@ -515,8 +516,7 @@ int vsp1_pipeline_stop(struct vsp1_pipeline *pipe)
> > > > >  			spin_unlock_irqrestore(&pipe->irqlock, flags);
> > > > >  		}
> > > > >
> > > > > -		if ((vsp1->version & VI6_IP_VERSION_MODEL_MASK) ==
> > > > > -		    VI6_IP_VERSION_MODEL_VSPD_GEN3)
> > > > > +		if (version == VI6_IP_VERSION_MODEL_VSPD_GEN3)
> > > > >  			ret |= rcar_fcp_soft_reset(vsp1->fcp);
> > > > >
> > > > >  	} else {
> > > > > @@ -529,6 +529,9 @@ int vsp1_pipeline_stop(struct vsp1_pipeline *pipe)
> > > > >  		ret = wait_event_timeout(pipe->wq, vsp1_pipeline_stopped(pipe),
> > > > >  					 msecs_to_jiffies(500));
> > > > >  		ret = ret == 0 ? -ETIMEDOUT : 0;
> > > > > +
> > > > > +		if (version == VI6_IP_VERSION_MODEL_VSPX_GEN4)
> > > > > +			ret |= rcar_fcp_soft_reset(vsp1->fcp);
> > > > >  	}
> > > > >
> > > > >  	list_for_each_entry(entity, &pipe->entities, list_pipe) {
> >
> > --
> > Regards,
> >
> > Laurent Pinchart

-- 
Kind Regards,
Niklas Söderlund