[PATCH v5 16/19] remoteproc: Properly deal with a stop request when attached

[Mathieu Poirier]

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.poir...@linaro.org>
Reviewed-by: Peng Fan <peng....@nxp.com>
Reviewed-by: Arnaud Pouliquen <arnaud.pouliq...@st.com>
---
 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 0dd9f02f52b6..12bd177aa8cd 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1740,6 +1740,10 @@ 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);
 
@@ -1977,7 +1981,7 @@ 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 f9694def9b54..3696f2ccc785 100644
--- a/drivers/remoteproc/remoteproc_sysfs.c
+++ b/drivers/remoteproc/remoteproc_sysfs.c
@@ -201,10 +201,11 @@ 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