> Subject: Re: [PATCH 3/9] remoteproc: support self recovery after rproc crash
>
> On Tue, Jan 11, 2022 at 11:33:27AM +0800, Peng Fan (OSS) wrote:
> > From: Peng Fan <peng.fan@xxxxxxx>
> >
> > Current logic only support main processor to stop/start the remote
> > processor after rproc crash. However to SoC, such as i.MX8QM/QXP, the
> > remote processor could do self recovery after crash and trigger
> > watchdog reboot. It does not need main processor to load image,
> > stop/start M4 core.
> >
> > This patch add a new flag to indicate whether the SoC has self
> > recovery capability. And introduce two functions: rproc_self_recovery,
> > rproc_assisted_recovery for the two cases. Assisted recovery is as
> > before, let main processor to help recovery, while self recovery is
> > recover itself withou help. To self recovery, we only do detach and
> > attach.
> >
> > Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
> > ---
> > drivers/remoteproc/remoteproc_core.c | 66
> ++++++++++++++++++++--------
> > include/linux/remoteproc.h | 2 +
> > 2 files changed, 49 insertions(+), 19 deletions(-)
> >
> > diff --git a/drivers/remoteproc/remoteproc_core.c
> > b/drivers/remoteproc/remoteproc_core.c
> > index 69f51acf235e..4bd5544dab8f 100644
> > --- a/drivers/remoteproc/remoteproc_core.c
> > +++ b/drivers/remoteproc/remoteproc_core.c
> > @@ -1887,6 +1887,49 @@ static int __rproc_detach(struct rproc *rproc)
> > return 0;
> > }
> >
> > +static int rproc_self_recovery(struct rproc *rproc) {
> > + int ret;
> > +
> > + mutex_unlock(&rproc->lock);
> > + ret = rproc_detach(rproc);
> > + mutex_lock(&rproc->lock);
> > + if (ret)
> > + return ret;
> > +
> > + if (atomic_inc_return(&rproc->power) > 1)
> > + return 0;
> > + return rproc_attach(rproc);
> > +}
> > +
> > +static int rproc_assisted_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
> > @@ -1901,7 +1944,6 @@ 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;
> >
> > @@ -1915,24 +1957,10 @@ 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->self_recovery)
> > + ret = rproc_self_recovery(rproc);
> > + else
> > + ret = rproc_assisted_recovery(rproc);
>
> The problem of how to handle crash recoveries for processors that have been
> attached to is difficult. Finding a solution for that should be on a patchset of
> its own so that people can provide input.
ok, will move this patch out from the patchset.
Thanks,
Peng.
>
> >
> > unlock_mutex:
> > mutex_unlock(&rproc->lock);
> > diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> > index e0600e1e5c17..b32ef46f8aa4 100644
> > --- a/include/linux/remoteproc.h
> > +++ b/include/linux/remoteproc.h
> > @@ -529,6 +529,7 @@ struct rproc_dump_segment {
> > * @elf_machine: firmware ELF machine
> > * @cdev: character device of the rproc
> > * @cdev_put_on_release: flag to indicate if remoteproc should be
> > shutdown on @char_dev release
> > + * @self_recovery: flag to indicate if remoteproc support self
> > + recovery
> > */
> > struct rproc {
> > struct list_head node;
> > @@ -568,6 +569,7 @@ struct rproc {
> > u16 elf_machine;
> > struct cdev cdev;
> > bool cdev_put_on_release;
> > + bool self_recovery;
> > };
> >
> > /**
> > --
> > 2.25.1
> >
