Searched hist:fa15d8c6 (Results 1 – 2 of 2) sorted by relevance
| /openbmc/linux/drivers/leds/ |
| H A D | led-core.c | fa15d8c6 Wed May 10 11:22:32 CDT 2023 Hans de Goede <hdegoede@redhat.com> leds: Fix set_brightness_delayed() race
When a trigger wants to switch from blinking to LED on it needs to call:
led_set_brightness(LED_OFF);
led_set_brightness(LED_FULL);
To first call disables blinking and the second then turns the LED on
(the power-supply charging-blink-full-solid triggers do this).
These calls happen immediately after each other, so it is possible
that set_brightness_delayed() from the first call has not run yet
when the led_set_brightness(LED_FULL) call finishes.
If this race hits then this is causing problems for both
sw- and hw-blinking:
For sw-blinking set_brightness_delayed() clears delayed_set_value
when LED_BLINK_DISABLE is set causing the led_set_brightness(LED_FULL)
call effects to get lost when hitting the race, resulting in the LED
turning off instead of on.
For hw-blinking if the race hits delayed_set_value has been
set to LED_FULL by the time set_brightness_delayed() runs.
So led_cdev->brightness_set_blocking() is never called with
LED_OFF as argument and the hw-blinking is never disabled leaving
the LED blinking instead of on.
Fix both issues by adding LED_SET_BRIGHTNESS and LED_SET_BRIGHTNESS_OFF
work_flags making this 2 separate actions to be run by
set_brightness_delayed().
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Tested-by: Yauhen Kharuzhy <jekhor@gmail.com>
Link: https://lore.kernel.org/r/20230510162234.291439-3-hdegoede@redhat.com
Signed-off-by: Lee Jones <lee@kernel.org>
|
| /openbmc/linux/include/linux/ |
| H A D | leds.h | fa15d8c6 Wed May 10 11:22:32 CDT 2023 Hans de Goede <hdegoede@redhat.com> leds: Fix set_brightness_delayed() race
When a trigger wants to switch from blinking to LED on it needs to call:
led_set_brightness(LED_OFF);
led_set_brightness(LED_FULL);
To first call disables blinking and the second then turns the LED on
(the power-supply charging-blink-full-solid triggers do this).
These calls happen immediately after each other, so it is possible
that set_brightness_delayed() from the first call has not run yet
when the led_set_brightness(LED_FULL) call finishes.
If this race hits then this is causing problems for both
sw- and hw-blinking:
For sw-blinking set_brightness_delayed() clears delayed_set_value
when LED_BLINK_DISABLE is set causing the led_set_brightness(LED_FULL)
call effects to get lost when hitting the race, resulting in the LED
turning off instead of on.
For hw-blinking if the race hits delayed_set_value has been
set to LED_FULL by the time set_brightness_delayed() runs.
So led_cdev->brightness_set_blocking() is never called with
LED_OFF as argument and the hw-blinking is never disabled leaving
the LED blinking instead of on.
Fix both issues by adding LED_SET_BRIGHTNESS and LED_SET_BRIGHTNESS_OFF
work_flags making this 2 separate actions to be run by
set_brightness_delayed().
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Tested-by: Yauhen Kharuzhy <jekhor@gmail.com>
Link: https://lore.kernel.org/r/20230510162234.291439-3-hdegoede@redhat.com
Signed-off-by: Lee Jones <lee@kernel.org>
|