[PATCH v4 14/17] remoteproc: Properly deal with a stop request when attached

[Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>]

This patch introduces the capability to stop a remote processor
that has been attached to by the remoteproc core.  For that to
happen a rproc::ops::stop() operation need to be available.

Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Reviewed-by: Peng Fan <peng.fan@xxxxxxx>
Reviewed-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>
---
 drivers/remoteproc/remoteproc_cdev.c  | 5 +++--
 drivers/remoteproc/remoteproc_core.c  | 6 +++++-
 drivers/remoteproc/remoteproc_sysfs.c | 5 +++--
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_cdev.c b/drivers/remoteproc/remoteproc_cdev.c
index b19ea3057bde..d06f8d4919c7 100644
--- a/drivers/remoteproc/remoteproc_cdev.c
+++ b/drivers/remoteproc/remoteproc_cdev.c
@@ -37,10 +37,11 @@ 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);
+		ret = rproc_shutdown(rproc);
 	} else {
 		dev_err(&rproc->dev, "Unrecognized option\n");
 		ret = -EINVAL;
diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index 90057ad1bb6c..2fe42ac7ca89 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1648,6 +1648,10 @@ 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);
 
@@ -1897,7 +1901,7 @@ int rproc_shutdown(struct rproc *rproc)
 		return ret;
 	}
 
-	if (rproc->state != RPROC_RUNNING) {
+	if (rproc->state != RPROC_RUNNING && rproc->state != RPROC_ATTACHED) {
 		ret = -EPERM;
 		goto out;
 	}
diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c
index 99ff51fd9707..96751c087585 100644
--- a/drivers/remoteproc/remoteproc_sysfs.c
+++ b/drivers/remoteproc/remoteproc_sysfs.c
@@ -230,10 +230,11 @@ 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);
+		ret = rproc_shutdown(rproc);
 	} else {
 		dev_err(&rproc->dev, "Unrecognised option: %s\n", buf);
 		ret = -EINVAL;
-- 
2.25.1