[PATCH v4 13/17] remoteproc: Add return value to function rproc_shutdown()

[Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>]

Add a return value to function rproc_shutdown() in order to
properly deal with error conditions that may occur.

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_core.c | 19 ++++++++++++++-----
 include/linux/remoteproc.h           |  2 +-
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index ece3f15070b9..90057ad1bb6c 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1886,7 +1886,7 @@ EXPORT_SYMBOL(rproc_boot);
  *   returns, and users can still use it with a subsequent rproc_boot(), if
  *   needed.
  */
-void rproc_shutdown(struct rproc *rproc)
+int rproc_shutdown(struct rproc *rproc)
 {
 	struct device *dev = &rproc->dev;
 	int ret;
@@ -1894,15 +1894,19 @@ void rproc_shutdown(struct rproc *rproc)
 	ret = mutex_lock_interruptible(&rproc->lock);
 	if (ret) {
 		dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret);
-		return;
+		return ret;
 	}
 
-	if (rproc->state != RPROC_RUNNING)
+	if (rproc->state != RPROC_RUNNING) {
+		ret = -EPERM;
 		goto out;
+	}
 
 	/* if the remote proc is still needed, bail out */
-	if (!atomic_dec_and_test(&rproc->power))
+	if (!atomic_dec_and_test(&rproc->power)) {
+		ret = -EBUSY;
 		goto out;
+	}
 
 	ret = rproc_stop(rproc, false);
 	if (ret) {
@@ -1914,7 +1918,11 @@ void rproc_shutdown(struct rproc *rproc)
 	rproc_resource_cleanup(rproc);
 
 	/* release HW resources if needed */
-	rproc_unprepare_device(rproc);
+	ret = rproc_unprepare_device(rproc);
+	if (ret) {
+		atomic_inc(&rproc->power);
+		goto out;
+	}
 
 	rproc_disable_iommu(rproc);
 
@@ -1924,6 +1932,7 @@ void rproc_shutdown(struct rproc *rproc)
 	rproc->table_ptr = NULL;
 out:
 	mutex_unlock(&rproc->lock);
+	return ret;
 }
 EXPORT_SYMBOL(rproc_shutdown);
 
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index 65ece6f177b7..aa5bceb72015 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -658,7 +658,7 @@ rproc_of_resm_mem_entry_init(struct device *dev, u32 of_resm_idx, size_t len,
 			     u32 da, const char *name, ...);
 
 int rproc_boot(struct rproc *rproc);
-void rproc_shutdown(struct rproc *rproc);
+int rproc_shutdown(struct rproc *rproc);
 int rproc_detach(struct rproc *rproc);
 int rproc_set_firmware(struct rproc *rproc, const char *fw_name);
 void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type);
-- 
2.25.1