From: Zihuan Zhang <zhangzihuan@kylinos.cn>
Date: Fri, 9 May 2025 02:25:54 +0000 (+0800)
Subject: HID: debug: Use the __set_current_state()
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d3db1ce9bf8f4a8e03d3bd19000b32290bca7d74;p=thirdparty%2Flinux.git

HID: debug: Use the __set_current_state()

When detecting an invalid list->hdev, the process needs to manually set
its state to TASK_RUNNING and exit. In the original code,
set_current_state() (which includes a memory barrier) is used here, but
it is immediately followed by a mutex_unlock() call. Since
mutex_unlock() internally includes a memory barrier, this ensures that
all modifications within the critical section (including the process
state) are visible to other CPUs. Therefore, replacing it with
__set_current_state() (without an implicit barrier) avoids redundant
memory barriers.

Signed-off-by: Zihuan Zhang <zhangzihuan@kylinos.cn>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
---

diff --git a/drivers/hid/hid-debug.c b/drivers/hid/hid-debug.c
index 8433306148d57..00a73983ef19b 100644
--- a/drivers/hid/hid-debug.c
+++ b/drivers/hid/hid-debug.c
@@ -3726,7 +3726,7 @@ static ssize_t hid_debug_events_read(struct file *file, char __user *buffer,
 			 */
 			if (!list->hdev || !list->hdev->debug) {
 				ret = -EIO;
-				set_current_state(TASK_RUNNING);
+				__set_current_state(TASK_RUNNING);
 				goto out;
 			}