[PATCH 1/2] remoteproc: core: Attach rproc asynchronously in rproc_add() path

[Jingyi Wang]

For rproc with state RPROC_DETACHED and auto_boot enabled, the attach
callback will be called in the rproc_add()->rproc_trigger_auto_boot()->
rproc_boot() path, the failure in this path will cause the rproc_add()
fail and the resource release, which will cause issue like rproc recovery
or falling back to firmware load fail. Add attach_work for rproc and call
it asynchronously in rproc_add() path like what rproc_start() do.

Signed-off-by: Jingyi Wang <jingyi.wang@xxxxxxxxxxxxxxxx>
---
 drivers/remoteproc/remoteproc_core.c | 20 ++++++++++++--------
 include/linux/remoteproc.h           |  1 +
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index b087ed21858a..f02db1113fae 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1673,18 +1673,21 @@ static void rproc_auto_boot_callback(const struct firmware *fw, void *context)
 	release_firmware(fw);
 }
 
+static void rproc_attach_work(struct work_struct *work)
+{
+	struct rproc *rproc = container_of(work, struct rproc, attach_work);
+
+	rproc_boot(rproc);
+}
+
 static int rproc_trigger_auto_boot(struct rproc *rproc)
 {
 	int ret;
 
-	/*
-	 * Since the remote processor is in a detached state, it has already
-	 * been booted by another entity.  As such there is no point in waiting
-	 * for a firmware image to be loaded, we can simply initiate the process
-	 * of attaching to it immediately.
-	 */
-	if (rproc->state == RPROC_DETACHED)
-		return rproc_boot(rproc);
+	if (rproc->state == RPROC_DETACHED) {
+		schedule_work(&rproc->attach_work);
+		return 0;
+	}
 
 	/*
 	 * We're initiating an asynchronous firmware loading, so we can
@@ -2512,6 +2515,7 @@ struct rproc *rproc_alloc(struct device *dev, const char *name,
 	INIT_LIST_HEAD(&rproc->dump_segments);
 
 	INIT_WORK(&rproc->crash_handler, rproc_crash_handler_work);
+	INIT_WORK(&rproc->attach_work, rproc_attach_work);
 
 	rproc->state = RPROC_OFFLINE;
 
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index b4795698d8c2..9b3f748e9eca 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -568,6 +568,7 @@ struct rproc {
 	struct list_head subdevs;
 	struct idr notifyids;
 	int index;
+	struct work_struct attach_work;
 	struct work_struct crash_handler;
 	unsigned int crash_cnt;
 	bool recovery_disabled;

-- 
2.34.1