[PATCH v2 3/4] remoteproc: core: Fix cdev remove and rproc del

[Siddharth Gupta]

The rproc_char_device_remove() call currently unmaps the cdev
region instead of simply deleting the cdev that was added as a
part of the rproc_char_device_add() call. This change fixes that
behaviour, and also fixes the order in which device_del() and
cdev_del() need to be called.

Signed-off-by: Siddharth Gupta <sidgup@xxxxxxxxxxxxxx>
---
 0000-cover-letter.patch.backup       | 26 ++++++++++++++++++++++++++
 drivers/remoteproc/remoteproc_cdev.c |  2 +-
 drivers/remoteproc/remoteproc_core.c |  2 +-
 3 files changed, 28 insertions(+), 2 deletions(-)
 create mode 100644 0000-cover-letter.patch.backup

diff --git a/0000-cover-letter.patch.backup b/0000-cover-letter.patch.backup
new file mode 100644
index 0000000..837bcdb
--- /dev/null
+++ b/0000-cover-letter.patch.backup
@@ -0,0 +1,26 @@
+From 78fcb27d574d2f7b06e37b77b257f98858a88d9d Mon Sep 17 00:00:00 2001
+From: Siddharth Gupta <sidgup@xxxxxxxxxxxxxx>
+Date: Mon, 17 May 2021 13:33:25 -0700
+Subject: [PATCH 0/3] remoteproc: core: Fixes for rproc cdev and add
+To: bjorn.andersson@xxxxxxxxxx,ohad@xxxxxxxxxx,linux-remoteproc@xxxxxxxxxxxxxxx
+Cc: linux-kernel@xxxxxxxxxxxxxxx,linux-arm-msm@xxxxxxxxxxxxxxx,linux-arm-kernel@xxxxxxxxxxxxxxxxxxx,psodagud@xxxxxxxxxxxxxx,stable@xxxxxxxxxxxxxxx
+
+This patch series contains stability fixes and error handling for remoteproc.
+
+The changes included in this series do the following:
+Patch 1: Fixes the creation of the rproc character device.
+Patch 2: Validates rproc as the first step of rproc_add().
+Patch 3: Adds error handling in rproc_add().
+
+Siddharth Gupta (3):
+  remoteproc: core: Move cdev add before device add
+  remoteproc: core: Move validate before device add
+  remoteproc: core: Cleanup device in case of failure
+
+ drivers/remoteproc/remoteproc_core.c | 25 +++++++++++++++++--------
+ 1 file changed, 17 insertions(+), 8 deletions(-)
+
+-- 
+Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
+a Linux Foundation Collaborative Project
+
diff --git a/drivers/remoteproc/remoteproc_cdev.c b/drivers/remoteproc/remoteproc_cdev.c
index 0b8a84c..4ad98b0 100644
--- a/drivers/remoteproc/remoteproc_cdev.c
+++ b/drivers/remoteproc/remoteproc_cdev.c
@@ -124,7 +124,7 @@ int rproc_char_device_add(struct rproc *rproc)
 
 void rproc_char_device_remove(struct rproc *rproc)
 {
-	__unregister_chrdev(MAJOR(rproc->dev.devt), rproc->index, 1, "remoteproc");
+	cdev_del(&rproc->cdev);
 }
 
 void __init rproc_init_cdev(void)
diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index b65fce3..b874280 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -2619,7 +2619,6 @@ int rproc_del(struct rproc *rproc)
 	mutex_unlock(&rproc->lock);
 
 	rproc_delete_debug_dir(rproc);
-	rproc_char_device_remove(rproc);
 
 	/* the rproc is downref'ed as soon as it's removed from the klist */
 	mutex_lock(&rproc_list_mutex);
@@ -2630,6 +2629,7 @@ int rproc_del(struct rproc *rproc)
 	synchronize_rcu();
 
 	device_del(&rproc->dev);
+	rproc_char_device_remove(rproc);
 
 	return 0;
 }
-- 
Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project