[PATCH v4 1/2] remoteproc: core: full attach detach during recovery

[Tanmay Shah <tanmay.shah@amd.com>]

Current attach on recovery mechanism loads the clean resource table
during recovery, but doesn't re-allocate the resources. RPMsg
communication will fail after recovery due to this. Fix this
incorrect behavior by doing the full detach and attach of remote
processor during the recovery. This will load the clean resource table
and re-allocate all the resources, which will set up correct vring
information in the resource table.

Signed-off-by: Tanmay Shah <tanmay.shah@amd.com>
---

Changes in v4:
 - move pieces needed from rproc_detach() to rproc_attach_recovery() to
   cleanup the resources
 - use rproc_attach() over __rproc_attach() to create resources again
 - keep rproc_trigger_recovery() unmodified

Changes in v3:
 - both rproc_attach_recovery() and
   rproc_boot_recovery() are called the same way.
 - remove unrelated changes

Changes in v2:
 - use rproc_boot instead of rproc_attach
 - move debug message early in the function

 drivers/remoteproc/remoteproc_core.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index b087ed21858a..d56788e8df76 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1781,7 +1781,20 @@ static int rproc_attach_recovery(struct rproc *rproc)
 	if (ret)
 		return ret;
 
-	return __rproc_attach(rproc);
+	/* clean up all acquired resources */
+	rproc_resource_cleanup(rproc);
+
+	/* release HW resources if needed */
+	rproc_unprepare_device(rproc);
+
+	rproc_disable_iommu(rproc);
+
+	/* Free the copy of the resource table */
+	kfree(rproc->cached_table);
+	rproc->cached_table = NULL;
+	rproc->table_ptr = NULL;
+
+	return rproc_attach(rproc);
 }
 
 static int rproc_boot_recovery(struct rproc *rproc)
-- 
2.34.1