The led_access lock must be held when calling led_sysfs_enable() and
led_sysfs_disable(). This fixes warnings such as this:
[ 2.432495] ------------[ cut here ]------------
[ 2.437316] WARNING: CPU: 0 PID: 22 at drivers/leds/led-core.c:349 led_sysfs_disable+0x54/0x58
[ 2.446105] Modules linked in:
[ 2.449218] CPU: 0 PID: 22 Comm: kworker/u2:1 Not tainted 6.3.8+ #1
[ 2.456268] Hardware name: Generic AM3517 (Flattened Device Tree)
[ 2.462402] Workqueue: events_unbound deferred_probe_work_func
[ 2.468353] unwind_backtrace from show_stack+0x10/0x14
[ 2.473632] show_stack from dump_stack_lvl+0x24/0x2c
[ 2.478759] dump_stack_lvl from __warn+0x9c/0xc4
[ 2.483551] __warn from warn_slowpath_fmt+0x64/0xc0
[ 2.488586] warn_slowpath_fmt from led_sysfs_disable+0x54/0x58
[ 2.494567] led_sysfs_disable from led_bl_probe+0x20c/0x3b0
[ 2.500305] led_bl_probe from platform_probe+0x5c/0xb8
[ 2.505615] platform_probe from really_probe+0xc8/0x2a0
[ 2.510986] really_probe from __driver_probe_device+0x88/0x19c
[ 2.516967] __driver_probe_device from driver_probe_device+0x30/0xcc
[ 2.523498] driver_probe_device from __device_attach_driver+0x94/0xc4
[ 2.530090] __device_attach_driver from bus_for_each_drv+0x80/0xcc
[ 2.536437] bus_for_each_drv from __device_attach+0xf8/0x19c
[ 2.542236] __device_attach from bus_probe_device+0x8c/0x90
[ 2.547973] bus_probe_device from deferred_probe_work_func+0x80/0xb0
[ 2.554504] deferred_probe_work_func from process_one_work+0x228/0x4c0
[ 2.561187] process_one_work from worker_thread+0x1fc/0x4d0
[ 2.566925] worker_thread from kthread+0xb4/0xd0
[ 2.571685] kthread from ret_from_fork+0x14/0x2c
[ 2.576446] Exception stack(0xd0079fb0 to 0xd0079ff8)
[ 2.581573] 9fa0: 00000000 00000000 00000000 00000000
[ 2.589813] 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 2.598052] 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
[ 2.604888] ---[ end trace 0000000000000000 ]---
Signed-off-by: Mans Rullgard <mans@xxxxxxxxx>
---
drivers/video/backlight/led_bl.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/video/backlight/led_bl.c b/drivers/video/backlight/led_bl.c
index f54d256e2d54..7d02deb3444a 100644
--- a/drivers/video/backlight/led_bl.c
+++ b/drivers/video/backlight/led_bl.c
@@ -209,8 +209,11 @@ static int led_bl_probe(struct platform_device *pdev)
return PTR_ERR(priv->bl_dev);
}
- for (i = 0; i < priv->nb_leds; i++)
+ for (i = 0; i < priv->nb_leds; i++) {
+ mutex_lock(&priv->leds[i]->led_access);
led_sysfs_disable(priv->leds[i]);
+ mutex_unlock(&priv->leds[i]->led_access);
+ }
backlight_update_status(priv->bl_dev);
--
2.41.0
