* [PATCH] backlight: led_bl: take led_access lock when required
@ 2023-06-19 16:02 Mans Rullgard
2023-06-26 14:27 ` Daniel Thompson
2023-06-26 15:30 ` Lee Jones
0 siblings, 2 replies; 3+ messages in thread
From: Mans Rullgard @ 2023-06-19 16:02 UTC (permalink / raw)
To: Lee Jones, Daniel Thompson, Jingoo Han
Cc: Tomi Valkeinen, dri-devel, linux-kernel
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@mansr.com>
---
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] backlight: led_bl: take led_access lock when required
2023-06-19 16:02 [PATCH] backlight: led_bl: take led_access lock when required Mans Rullgard
@ 2023-06-26 14:27 ` Daniel Thompson
2023-06-26 15:30 ` Lee Jones
1 sibling, 0 replies; 3+ messages in thread
From: Daniel Thompson @ 2023-06-26 14:27 UTC (permalink / raw)
To: Mans Rullgard
Cc: Lee Jones, Jingoo Han, Tomi Valkeinen, dri-devel, linux-kernel
On Mon, Jun 19, 2023 at 05:02:49PM +0100, Mans Rullgard wrote:
> 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@mansr.com>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Daniel.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] backlight: led_bl: take led_access lock when required
2023-06-19 16:02 [PATCH] backlight: led_bl: take led_access lock when required Mans Rullgard
2023-06-26 14:27 ` Daniel Thompson
@ 2023-06-26 15:30 ` Lee Jones
1 sibling, 0 replies; 3+ messages in thread
From: Lee Jones @ 2023-06-26 15:30 UTC (permalink / raw)
To: Mans Rullgard
Cc: Daniel Thompson, Jingoo Han, Tomi Valkeinen, dri-devel,
linux-kernel
On Mon, 19 Jun 2023, Mans Rullgard wrote:
> 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@mansr.com>
> ---
> drivers/video/backlight/led_bl.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
Applied, thanks
--
Lee Jones [李琼斯]
^ permalink raw reply [flat|nested] 3+ messages in thread
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2023-06-19 16:02 [PATCH] backlight: led_bl: take led_access lock when required Mans Rullgard
2023-06-26 14:27 ` Daniel Thompson
2023-06-26 15:30 ` Lee Jones
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