From 5a2d96623670155d94aca72c320c0ac27bdc6bd2 Mon Sep 17 00:00:00 2001
From: Yuan Can <yuancan@huawei.com>
Date: Thu, 17 Nov 2022 08:08:23 +0000
Subject: [PATCH] platform/chrome: cros_usbpd_notify: Fix error handling in cros_usbpd_notify_init()
Git-commit: 5a2d96623670155d94aca72c320c0ac27bdc6bd2
Patch-mainline: v6.2-rc1
References: git-fixes

The following WARNING message was given when rmmod cros_usbpd_notify:

 Unexpected driver unregister!
 WARNING: CPU: 0 PID: 253 at drivers/base/driver.c:270 driver_unregister+0x8a/0xb0
 Modules linked in: cros_usbpd_notify(-)
 CPU: 0 PID: 253 Comm: rmmod Not tainted 6.1.0-rc3 #24
 ...
 Call Trace:
  <TASK>
  cros_usbpd_notify_exit+0x11/0x1e [cros_usbpd_notify]
  __x64_sys_delete_module+0x3c7/0x570
  ? __ia32_sys_delete_module+0x570/0x570
  ? lock_is_held_type+0xe3/0x140
  ? syscall_enter_from_user_mode+0x17/0x50
  ? rcu_read_lock_sched_held+0xa0/0xd0
  ? syscall_enter_from_user_mode+0x1c/0x50
  do_syscall_64+0x37/0x90
  entry_SYSCALL_64_after_hwframe+0x63/0xcd
 RIP: 0033:0x7f333fe9b1b7

The reason is that the cros_usbpd_notify_init() does not check the return
value of platform_driver_register(), and the cros_usbpd_notify can
install successfully even if platform_driver_register() failed.

Fix by checking the return value of platform_driver_register() and
unregister cros_usbpd_notify_plat_driver when it failed.

Fixes: ec2daf6e33f9 ("platform: chrome: Add cros-usbpd-notify driver")
Signed-off-by: Yuan Can <yuancan@huawei.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Link: https://lore.kernel.org/r/20221117080823.77549-1-yuancan@huawei.com
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/platform/chrome/cros_usbpd_notify.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/chrome/cros_usbpd_notify.c b/drivers/platform/chrome/cros_usbpd_notify.c
index 4b5a81c9dc6d..10670b6588e3 100644
--- a/drivers/platform/chrome/cros_usbpd_notify.c
+++ b/drivers/platform/chrome/cros_usbpd_notify.c
@@ -239,7 +239,11 @@ static int __init cros_usbpd_notify_init(void)
 		return ret;
 
 #ifdef CONFIG_ACPI
-	platform_driver_register(&cros_usbpd_notify_acpi_driver);
+	ret = platform_driver_register(&cros_usbpd_notify_acpi_driver);
+	if (ret) {
+		platform_driver_unregister(&cros_usbpd_notify_plat_driver);
+		return ret;
+	}
 #endif
 	return 0;
 }
-- 
2.35.3