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

[Mathieu Poirier]

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@xxxxxxxxxx>
---
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;
-- 
2.25.1