led_set_brightness() involves scheduling a workqueue. As here the led's
brightness setting is done in context of the trigger's workqueue this is
unjustified overhead and it's more sensible to use
led_set_brightness_sync().
Fixes: fd4a641ac8 ("leds: trigger: implement a tty trigger")
Reported-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210219133307.4840-3-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ttyname is allocated before the mutex is taken, so it must not be
unlocked in the error path.
Fixes: fd4a641ac8 ("leds: trigger: implement a tty trigger")
Reported-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210219133307.4840-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Usage is as follows:
myled=ledname
tty=ttyS0
echo tty > /sys/class/leds/$myled/trigger
echo $tty > /sys/class/leds/$myled/ttyname
. When this new trigger is active it periodically checks the tty's
statistics and when it changed since the last check the led is flashed
once.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210113173018.bq2fkea2o3yp6rf6@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
