linux-kernel - RE: [PATCH V7 2/2] remoteproc: support attach recovery after rproc crash

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Date:   Tue, 27 Sep 2022 03:03:06 +0000
From:   Peng Fan <peng.fan@....com>
To:     Mathieu Poirier <mathieu.poirier@...aro.org>,
        "Peng Fan (OSS)" <peng.fan@....nxp.com>,
        Bjorn Andersson <andersson@...nel.org>
CC:     "bjorn.andersson@...aro.org" <bjorn.andersson@...aro.org>,
        "arnaud.pouliquen@...s.st.com" <arnaud.pouliquen@...s.st.com>,
        "linux-remoteproc@...r.kernel.org" <linux-remoteproc@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH V7 2/2] remoteproc: support attach recovery after rproc
 crash

Hi Mathieu,

> Subject: Re: [PATCH V7 2/2] remoteproc: support attach recovery after rproc
> crash
> 
> On Tue, Jul 05, 2022 at 09:15:27AM +0800, Peng Fan (OSS) wrote:
> > From: Peng Fan <peng.fan@....com>
> >
> > Current logic only support main processor to stop/start the remote
> > processor after crash. However to SoC, such as i.MX8QM/QXP, the remote
> > processor could do attach recovery after crash and trigger watchdog to
> > reboot itself. It does not need main processor to load image, or
> > stop/start remote processor.
> >
> > Introduce two functions: rproc_attach_recovery, rproc_boot_recovery
> > for the two cases. Boot recovery is as before, let main processor to
> > help recovery, while attach recovery is to recover itself without help.
> > To attach recovery, we only do detach and attach.
> >
> > Acked-by: Arnaud Pouliquen <arnaud.pouliquen@...s.st.com>
> > Signed-off-by: Peng Fan <peng.fan@....com>
> > ---
> >  drivers/remoteproc/remoteproc_core.c | 62
> > +++++++++++++++++++---------
> >  1 file changed, 43 insertions(+), 19 deletions(-)
> >
> > diff --git a/drivers/remoteproc/remoteproc_core.c
> > b/drivers/remoteproc/remoteproc_core.c
> > index ed374c8bf14a..ef5b9310bc83 100644
> > --- a/drivers/remoteproc/remoteproc_core.c
> > +++ b/drivers/remoteproc/remoteproc_core.c
> > @@ -1884,6 +1884,45 @@ static int __rproc_detach(struct rproc *rproc)
> >  	return 0;
> >  }
> >
> > +static int rproc_attach_recovery(struct rproc *rproc) {
> > +	int ret;
> > +
> > +	ret = __rproc_detach(rproc);
> > +	if (ret)
> > +		return ret;
> 
> I thought there was a specific reason to _not_ call rproc->ops->coredump()
> for processors that have been attached to but looking at the STM32 and
> IMX_DSP now, it would seem logical to do so.  Am I missing something?

ATTACH RECOVERY is to support recovery without help from Linux,

STM32 and IMX_DSP, both require linux to load image and start remote
core. So the two cases should not enable feature:
RPROC_FEAT_ATTACH_ON_RECOVERY

Also considering the recovery is out of linux control, actually when linux
start dump, remote core may already recovered. 

> 
> And this set will need a rebase.

I'll do the rebase and send V8 if the upper explanation could eliminate
your concern.

Thanks,
Peng.

> 
> Thanks,
> Mathieu
> 
> > +
> > +	return __rproc_attach(rproc);
> > +}
> > +
> > +static int rproc_boot_recovery(struct rproc *rproc) {
> > +	const struct firmware *firmware_p;
> > +	struct device *dev = &rproc->dev;
> > +	int ret;
> > +
> > +	ret = rproc_stop(rproc, true);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/* generate coredump */
> > +	rproc->ops->coredump(rproc);
> > +
> > +	/* load firmware */
> > +	ret = request_firmware(&firmware_p, rproc->firmware, dev);
> > +	if (ret < 0) {
> > +		dev_err(dev, "request_firmware failed: %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	/* boot the remote processor up again */
> > +	ret = rproc_start(rproc, firmware_p);
> > +
> > +	release_firmware(firmware_p);
> > +
> > +	return ret;
> > +}
> > +
> >  /**
> >   * rproc_trigger_recovery() - recover a remoteproc
> >   * @rproc: the remote processor
> > @@ -1898,7 +1937,6 @@ static int __rproc_detach(struct rproc *rproc)
> >   */
> >  int rproc_trigger_recovery(struct rproc *rproc)  {
> > -	const struct firmware *firmware_p;
> >  	struct device *dev = &rproc->dev;
> >  	int ret;
> >
> > @@ -1912,24 +1950,10 @@ int rproc_trigger_recovery(struct rproc
> > *rproc)
> >
> >  	dev_err(dev, "recovering %s\n", rproc->name);
> >
> > -	ret = rproc_stop(rproc, true);
> > -	if (ret)
> > -		goto unlock_mutex;
> > -
> > -	/* generate coredump */
> > -	rproc->ops->coredump(rproc);
> > -
> > -	/* load firmware */
> > -	ret = request_firmware(&firmware_p, rproc->firmware, dev);
> > -	if (ret < 0) {
> > -		dev_err(dev, "request_firmware failed: %d\n", ret);
> > -		goto unlock_mutex;
> > -	}
> > -
> > -	/* boot the remote processor up again */
> > -	ret = rproc_start(rproc, firmware_p);
> > -
> > -	release_firmware(firmware_p);
> > +	if (rproc_has_feature(rproc, RPROC_FEAT_ATTACH_ON_RECOVERY))
> > +		ret = rproc_attach_recovery(rproc);
> > +	else
> > +		ret = rproc_boot_recovery(rproc);
> >
> >  unlock_mutex:
> >  	mutex_unlock(&rproc->lock);
> > --
> > 2.25.1
> >