linux-kernel - RE: [PATCH V6 7/7] remoteproc: imx_rproc: Enable attach recovery for i.MX8QM/QXP

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Message-ID: <DU0PR04MB9417D403F16C843AF0E2472E88259@DU0PR04MB9417.eurprd04.prod.outlook.com>
Date:   Thu, 13 Oct 2022 13:11:00 +0000
From:   Peng Fan <peng.fan@....com>
To:     Mathieu Poirier <mathieu.poirier@...aro.org>,
        "Peng Fan (OSS)" <peng.fan@....nxp.com>
CC:     "andersson@...nel.org" <andersson@...nel.org>,
        "robh+dt@...nel.org" <robh+dt@...nel.org>,
        "krzysztof.kozlowski+dt@...aro.org" 
        <krzysztof.kozlowski+dt@...aro.org>,
        "shawnguo@...nel.org" <shawnguo@...nel.org>,
        "s.hauer@...gutronix.de" <s.hauer@...gutronix.de>,
        "kernel@...gutronix.de" <kernel@...gutronix.de>,
        "festevam@...il.com" <festevam@...il.com>,
        dl-linux-imx <linux-imx@....com>,
        "linux-remoteproc@...r.kernel.org" <linux-remoteproc@...r.kernel.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH V6 7/7] remoteproc: imx_rproc: Enable attach recovery for
 i.MX8QM/QXP

Hi Mathieu,

> Subject: Re: [PATCH V6 7/7] remoteproc: imx_rproc: Enable attach recovery
> for i.MX8QM/QXP
> 
> On Thu, Sep 29, 2022 at 02:17:04PM +0800, Peng Fan (OSS) wrote:
> > From: Peng Fan <peng.fan@....com>
> >
> > i.MX8QM/QXP M4 could recover without help from Linux, so to support it:
> >  - enable feature RPROC_FEAT_ATTACH_ON_RECOVERY
> >  - add detach hook
> >  - Since we have detach callback, we could move the free mbox
> > operation  from partition reset notify to detach callback.
> >
> > Signed-off-by: Peng Fan <peng.fan@....com>
> > ---
> >  drivers/remoteproc/imx_rproc.c | 22 +++++++++++++++++++---
> >  1 file changed, 19 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/remoteproc/imx_rproc.c
> > b/drivers/remoteproc/imx_rproc.c index bece44b46719..4057d6f33813
> > 100644
> > --- a/drivers/remoteproc/imx_rproc.c
> > +++ b/drivers/remoteproc/imx_rproc.c
> > @@ -603,6 +603,22 @@ static int imx_rproc_attach(struct rproc *rproc)
> >  	return imx_rproc_xtr_mbox_init(rproc);  }
> >
> > +static int imx_rproc_detach(struct rproc *rproc) {
> > +	struct imx_rproc *priv = rproc->priv;
> > +	const struct imx_rproc_dcfg *dcfg = priv->dcfg;
> > +
> > +	if (dcfg->method != IMX_RPROC_SCU_API)
> > +		return -EOPNOTSUPP;
> > +
> > +	if (imx_sc_rm_is_resource_owned(priv->ipc_handle, priv->rsrc_id))
> > +		return -EOPNOTSUPP;
> > +
> > +	imx_rproc_free_mbox(rproc);
> 
> Which is exactly what you did here.
> 
> I really don't understand what you did in patch 6/7...  Anyways, I suggest to
> add support for the detached scenario and then fix the mailbox corruption
> problem.

When CM4 doing attach recovery, the mbox channel needs to be released,
then attach function will request the mbox channel again.

So the flow is 
CM4(attach->request mbox)->CM4 crash notify Linux[1]->Linux got notification
->Linux detach(release mbox)[2]->Linux re-attach(request mbox)

Since patch 7/7 is to support attach recovery, so I move mbox free
from [1] to [2].

> 
> I am done reviewing this set.

Thanks for your time.

Thanks,
Peng.
> 
> > +
> > +	return 0;
> > +}
> > +
> >  static struct resource_table *imx_rproc_get_loaded_rsc_table(struct
> > rproc *rproc, size_t *table_sz)  {
> >  	struct imx_rproc *priv = rproc->priv; @@ -618,6 +634,7 @@ static
> > struct resource_table *imx_rproc_get_loaded_rsc_table(struct rproc
> > *rproc  static const struct rproc_ops imx_rproc_ops = {
> >  	.prepare	= imx_rproc_prepare,
> >  	.attach		= imx_rproc_attach,
> > +	.detach		= imx_rproc_detach,
> >  	.start		= imx_rproc_start,
> >  	.stop		= imx_rproc_stop,
> >  	.kick		= imx_rproc_kick,
> > @@ -797,8 +814,6 @@ static int imx_rproc_partition_notify(struct
> notifier_block *nb,
> >  	if (!((event & BIT(priv->rproc_pt)) && (*(u8 *)group ==
> IMX_SC_IRQ_GROUP_REBOOTED)))
> >  		return 0;
> >
> > -	imx_rproc_free_mbox(priv->rproc);
> > -
> >  	rproc_report_crash(priv->rproc, RPROC_WATCHDOG);
> >
> >  	pr_info("Partition%d reset!\n", priv->rproc_pt); @@ -916,7 +931,8
> @@
> > static int imx_rproc_detect_mode(struct imx_rproc *priv)
> >  		}
> >
> >  		priv->rproc->state = RPROC_DETACHED;
> > -		priv->rproc->recovery_disabled = true;
> > +		priv->rproc->recovery_disabled = false;
> > +		rproc_set_feature(priv->rproc,
> RPROC_FEAT_ATTACH_ON_RECOVERY);
> >
> >  		/* Get partition id and enable irq in SCFW */
> >  		ret = imx_sc_rm_get_resource_owner(priv->ipc_handle,
> priv->rsrc_id,
> > &pt);
> > --
> > 2.37.1
> >