Re: [PATCH v6 15/16] remoteproc: Properly deal with a detach request when attached

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

On 2/24/21 12:35 AM, Mathieu Poirier wrote:
> This patch introduces the capability to detach a remote processor
> that has been attached by the remoteproc core.  For that to happen
> a rproc::ops::detach() 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:
> - The RPROC_RUNNING -> RPROC_DETACHED transition is no longer permitted
>   to avoid dealing with complex resource table management problems.
> - Removed Peng and Arnaud's RB tags because of the above.
> ---
> 
>  drivers/remoteproc/remoteproc_cdev.c  | 5 +++++
>  drivers/remoteproc/remoteproc_sysfs.c | 5 +++++
>  2 files changed, 10 insertions(+)
> 
> diff --git a/drivers/remoteproc/remoteproc_cdev.c b/drivers/remoteproc/remoteproc_cdev.c
> index 0249d8f6c3f8..2db494816d5f 100644
> --- a/drivers/remoteproc/remoteproc_cdev.c
> +++ b/drivers/remoteproc/remoteproc_cdev.c
> @@ -43,6 +43,11 @@ static ssize_t rproc_cdev_write(struct file *filp, const char __user *buf, size_
>  			return -EINVAL;
>  
>  		rproc_shutdown(rproc);
> +	} else if (!strncmp(cmd, "detach", len)) {
> +		if (rproc->state != RPROC_ATTACHED)
> +			return -EINVAL;
> +
> +		ret = rproc_detach(rproc);
>  	} else {
>  		dev_err(&rproc->dev, "Unrecognized option\n");
>  		ret = -EINVAL;
> diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c
> index 09eb700c5e7e..ad3dd208024c 100644
> --- a/drivers/remoteproc/remoteproc_sysfs.c
> +++ b/drivers/remoteproc/remoteproc_sysfs.c
> @@ -207,6 +207,11 @@ static ssize_t state_store(struct device *dev,
>  			return -EINVAL;
>  
>  		rproc_shutdown(rproc);
> +	} else if (sysfs_streq(buf, "detach")) {
> +		if (rproc->state != RPROC_ATTACHED)
> +			return -EINVAL;
> +
> +		ret = rproc_detach(rproc);
>  	} else {
>  		dev_err(&rproc->dev, "Unrecognised option: %s\n", buf);
>  		ret = -EINVAL;
>