Re: [PATCH v6 14/16] remoteproc: Properly deal with a stop request when attached

[Arnaud POULIQUEN <arnaud.pouliquen@foss.st.com>]

On 2/24/21 12:35 AM, Mathieu Poirier wrote:
> Allow a remote processor that was started by another entity to be
> switched off by the remoteproc core.  For that to happen a
> rproc::ops::stop() operation needs to be available.
> 
> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

Reviewed-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>

Thanks,
Arnaud

> ---
> New for V6:
> - Removed state check in rproc_shutdown() as it is already done in
>   in calling functions.
> - rproc_shutdown() doesn't return an error code to keep legacy behevior.
> - Removed Peng and Arnaud's RB tags because of the above.
> ---
> 
>  drivers/remoteproc/remoteproc_cdev.c  | 3 ++-
>  drivers/remoteproc/remoteproc_core.c  | 4 ++++
>  drivers/remoteproc/remoteproc_sysfs.c | 3 ++-
>  3 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/remoteproc/remoteproc_cdev.c b/drivers/remoteproc/remoteproc_cdev.c
> index b2cee9afb41b..0249d8f6c3f8 100644
> --- a/drivers/remoteproc/remoteproc_cdev.c
> +++ b/drivers/remoteproc/remoteproc_cdev.c
> @@ -38,7 +38,8 @@ static ssize_t rproc_cdev_write(struct file *filp, const char __user *buf, size_
>  
>  		ret = rproc_boot(rproc);
>  	} else if (!strncmp(cmd, "stop", len)) {
> -		if (rproc->state != RPROC_RUNNING)
> +		if (rproc->state != RPROC_RUNNING &&
> +		    rproc->state != RPROC_ATTACHED)
>  			return -EINVAL;
>  
>  		rproc_shutdown(rproc);
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 0dc518a24104..00452da25fba 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -1758,6 +1758,10 @@ static int rproc_stop(struct rproc *rproc, bool crashed)
>  	struct device *dev = &rproc->dev;
>  	int ret;
>  
> +	/* No need to continue if a stop() operation has not been provided */
> +	if (!rproc->ops->stop)
> +		return -EINVAL;
> +
>  	/* Stop any subdevices for the remote processor */
>  	rproc_stop_subdevices(rproc, crashed);
>  
> diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c
> index 66801e6fe5cd..09eb700c5e7e 100644
> --- a/drivers/remoteproc/remoteproc_sysfs.c
> +++ b/drivers/remoteproc/remoteproc_sysfs.c
> @@ -202,7 +202,8 @@ 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_ATTACHED)
>  			return -EINVAL;
>  
>  		rproc_shutdown(rproc);
>