On Sat, Sep 13, 2025 at 12:25:16AM +0800, GuangFei Luo wrote:
Hi Greg,
Thanks for your review and suggestion.
I've updated sysfs_add_battery() to address your comment. The locking is now applied explicitly inside the function to prevent re-entry issues, while keeping the function self-contained for all call sites.
Patch version: v3
Thanks, GuangFei
v3:
- Modified the earlier approach: since sysfs_add_battery() is invoked from multiple places, the most reliable way is to add the lock inside the function itself.
- sysfs_remove_battery() had a similar race issue in the past, which was fixed by adding a lock as well. Reference: https://lore.kernel.org/all/9c921c22a7f33397a6774d7fa076db9b6a0fd669
.1312318300.git.len.brown@intel.com/
v2:
- Fix missing mutex_unlock in acpi_battery_update() (Reported-by: kernel test robot)
v1: When removing and reinserting the laptop battery, ACPI can trigger two notifications in quick succession:
Note, none of the above should be here in the changelog body, it should be below the --- line.
diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c index 6905b56bf3e4..f6d4a8b39a9c 100644 --- a/drivers/acpi/battery.c +++ b/drivers/acpi/battery.c @@ -850,6 +850,12 @@ static void __exit battery_hook_exit(void) static int sysfs_add_battery(struct acpi_battery *battery) {
- mutex_lock(&battery->sysfs_lock);
Again, can you use guard() to make this logic simpler? That would turn this into a much smaller patch.
thanks,
greg k-h