On 12/18/20 6:32 PM, Mathieu Poirier wrote:
> Introduce function __rproc_detach() to perform the same kind of
> operation as rproc_stop(), but instead of switching off the
> remote processor using rproc->ops->stop(), it uses
> rproc->ops->detach(). That way it is possible for the core
> to release the resources associated with a remote processor while
> the latter is kept operating.
>
> Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> Reviewed-by: Peng Fan <peng.fan@xxxxxxx>
> ---
> drivers/remoteproc/remoteproc_core.c | 42 ++++++++++++++++++++++++++++
> 1 file changed, 42 insertions(+)
>
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index fc28053c7f89..e665ed4776c3 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -1670,6 +1670,48 @@ static int rproc_stop(struct rproc *rproc, bool crashed)
> return 0;
> }
>
> +/*
> + * __rproc_detach(): Does the opposite of rproc_attach()
> + */
> +static int __maybe_unused __rproc_detach(struct rproc *rproc)
> +{
> + struct device *dev = &rproc->dev;
> + int ret;
> +
> + /* No need to continue if a detach() operation has not been provided */
> + if (!rproc->ops->detach)
> + return -EINVAL;
I wonder if this ops should be optional.
> +
> + /* Stop any subdevices for the remote processor */
> + rproc_stop_subdevices(rproc, false);
> +
> + /*
> + * If the remote processors was started by the core then a cached_table
> + * is present and we must follow the same cleanup sequence as we would
> + * for a shutdown(). As it is in rproc_stop(), use the cached resource
> + * table for the rest of the detach process since ->table_ptr will
> + * become invalid as soon as carveouts are released in
> + * rproc_resource_cleanup().
> + */
> + if (rproc->cached_table)
> + rproc->table_ptr = rproc->cached_table;
> +
> + /* Tell the remote processor the core isn't available anymore */
> + ret = rproc->ops->detach(rproc);
> + if (ret) {
> + dev_err(dev, "can't detach from rproc: %d\n", ret);
> + rproc_start_subdevices(rproc);
Not sure that this would be possible in all cases, without a unprepare and
prepare. What about having the same behavior as the rproc_stop failure?
Thanks
Arnaud.
> + return ret;
> + }
> +
> + rproc_unprepare_subdevices(rproc);
> +
> + rproc->state = RPROC_DETACHED;
> +
> + dev_info(dev, "detached remote processor %s\n", rproc->name);
> +
> + return 0;
> +}
>
> /**
> * rproc_trigger_recovery() - recover a remoteproc
>
