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

Peng Fan
2022-09-27T03:10:59Z

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@nxp.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@foss.st.com>
> > Signed-off-by: Peng Fan <peng.fan@nxp.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
> >