Re: [RFC 1/2] remoteproc: sysfs: authorize rproc shutdown when rproc is crashed

Mathieu Poirier
2020-03-11T21:45:13Z

Hi Loic,

On Wed, Mar 11, 2020 at 11:54:31AM +0100, Loic Pallardy wrote:
> When remoteproc recovery is disabled and rproc crashed, user space
> client has no way to reboot co-processor except by a complete platform
> reboot.
> Indeed rproc_shutdown() is called by sysfs state_store() only is rproc
> state is RPROC_RUNNING.
>
> This patch offers the possibility to shutdown the co-processor if
> it is in RPROC_CRASHED state and so to restart properly co-processor
> from sysfs interface.

And it is not possible to use the debugfs interface [1] to restart the MCU?

[1]. https://elixir.bootlin.com/linux/v5.6-rc2/source/drivers/remoteproc/remoteproc_debugfs.c#L147

>
> Signed-off-by: Loic Pallardy <loic.pallardy@st.com>
> ---
> drivers/remoteproc/remoteproc_core.c | 2 +-
> drivers/remoteproc/remoteproc_sysfs.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 097f33e4f1f3..7ac87a75cd1b 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -1812,7 +1812,7 @@ void rproc_shutdown(struct rproc *rproc)
> if (!atomic_dec_and_test(&rproc->power))
> goto out;
>
> - ret = rproc_stop(rproc, false);
> + ret = rproc_stop(rproc, rproc->state == RPROC_CRASHED);
> if (ret) {
> atomic_inc(&rproc->power);
> goto out;
> diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c
> index 7f8536b73295..1029458a4678 100644
> --- a/drivers/remoteproc/remoteproc_sysfs.c
> +++ b/drivers/remoteproc/remoteproc_sysfs.c
> @@ -101,7 +101,7 @@ static ssize_t state_store(struct device *dev,
> if (ret)
> dev_err(&rproc->dev, "Boot failed: %d\n", ret);
> } else if (sysfs_streq(buf, "stop")) {
> - if (rproc->state != RPROC_RUNNING)
> + if (rproc->state != RPROC_RUNNING && rproc->state != RPROC_CRASHED)
> return -EINVAL;
>
> rproc_shutdown(rproc);
> --
> 2.7.4
>