RE: [PATCH 04/10] remoteproc: imx_rproc: make syscon optional

[Peng Fan <peng.fan@nxp.com>]

> Subject: Re: [PATCH 04/10] remoteproc: imx_rproc: make syscon optional
> 
> Hi Peng,
> 
> On Fri, Jul 24, 2020 at 04:08:07PM +0800, Peng Fan wrote:
> > Make syscon optional, since i.MX8QM/QXP/7ULP not have SRC to control
> M4.
> > But currently i.MX8QM/QXP/7ULP not added, so still check regmap when
> > start/stop to avoid unhappy things.
> 
> On the i.MX8QM/QXP/7ULP processors, the remote processors are not
> handled by the remoteproc cores, as implemented in this patch.  In such a
> scenario how does the remoteproc core know the remote processor has
> crashed and how does it recover from such a condition?

For 7ULP dual boot case, A7 is under control of M4, so if m4 crash, I suppose
A7 would not work properly.

For 8QM/QXP partition case, M4 is in a standalone partition, if M4 crash or
reboot, the system controller unit will restart M4 and notify Acore that M4
restart.

Thanks,
Peng.

> 
> Thanks,
> Mathieu
> 
> >
> > Reviewed-by: Richard Zhu <hongxing.zhu@nxp.com>
> > Signed-off-by: Peng Fan <peng.fan@nxp.com>
> > ---
> >  drivers/remoteproc/imx_rproc.c | 11 +++++++++--
> >  1 file changed, 9 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/remoteproc/imx_rproc.c
> > b/drivers/remoteproc/imx_rproc.c index 82594a800a1b..4fad5c0b1c05
> > 100644
> > --- a/drivers/remoteproc/imx_rproc.c
> > +++ b/drivers/remoteproc/imx_rproc.c
> > @@ -162,6 +162,9 @@ static int imx_rproc_start(struct rproc *rproc)
> >  	struct device *dev = priv->dev;
> >  	int ret;
> >
> > +	if (!priv->regmap)
> > +		return -EOPNOTSUPP;
> > +
> >  	ret = regmap_update_bits(priv->regmap, dcfg->src_reg,
> >  				 dcfg->src_mask, dcfg->src_start);
> >  	if (ret)
> > @@ -177,6 +180,9 @@ static int imx_rproc_stop(struct rproc *rproc)
> >  	struct device *dev = priv->dev;
> >  	int ret;
> >
> > +	if (!priv->regmap)
> > +		return -EOPNOTSUPP;
> > +
> >  	ret = regmap_update_bits(priv->regmap, dcfg->src_reg,
> >  				 dcfg->src_mask, dcfg->src_stop);
> >  	if (ret)
> > @@ -325,9 +331,10 @@ static int imx_rproc_probe(struct platform_device
> *pdev)
> >  	regmap = syscon_regmap_lookup_by_phandle(np, "syscon");
> >  	if (IS_ERR(regmap)) {
> >  		dev_err(dev, "failed to find syscon\n");
> > -		return PTR_ERR(regmap);
> > +		regmap = NULL;
> > +	} else {
> > +		regmap_attach_dev(dev, regmap, &config);
> >  	}
> > -	regmap_attach_dev(dev, regmap, &config);
> >
> >  	/* set some other name then imx */
> >  	rproc = rproc_alloc(dev, "imx-rproc", &imx_rproc_ops,
> > --
> > 2.16.4
> >