leds: ledtrig-tty: Free allocated ttyname buffer on deactivate

commit 25054b232681c286fca9c678854f56494d1352cc upstream.

The ttyname buffer for the ledtrig_tty_data struct is allocated in the
sysfs

leds: ledtrig-tty: Free allocated ttyname buffer on deactivate

commit 25054b232681c286fca9c678854f56494d1352cc upstream.

The ttyname buffer for the ledtrig_tty_data struct is allocated in the
sysfs ttyname_store() function. This buffer must be released on trigger
deactivation. This was missing and is thus a memory leak.

While we are at it, the TTY handler in the ledtrig_tty_data struct should
also be returned in case of the trigger deactivation call.

Cc: stable@vger.kernel.org
Fixes: fd4a641ac88f ("leds: trigger: implement a tty trigger")
Signed-off-by: Florian Eckert <fe@dev.tdt.de>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20231127081621.774866-1-fe@dev.tdt.de
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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leds: trigger: tty: Do not use LED_ON/OFF constants, use led_blink_set_oneshot instead

The tty LED trigger uses the obsolete LED_ON & LED_OFF constants when
setting LED brightness. This is bad becau

leds: trigger: tty: Do not use LED_ON/OFF constants, use led_blink_set_oneshot instead

The tty LED trigger uses the obsolete LED_ON & LED_OFF constants when
setting LED brightness. This is bad because the LED_ON constant is equal
to 1, and so when activating the tty LED trigger on a LED class device
with max_brightness greater than 1, the LED is dimmer than it can be
(when max_brightness is 255, the LED is very dimm indeed; some devices
translate 1/255 to 0, so the LED is OFF all the time).

Instead of directly setting brightness to a specific value, use the
led_blink_set_oneshot() function from LED core to configure the blink.
This function takes the current configured brightness as blink
brightness if not zero, and max brightness otherwise.

This also changes the behavior of the TTY LED trigger. Previously if
rx/tx stats kept changing, the LED was ON all the time they kept
changing. With this patch the LED will blink on TTY activity.

Fixes: fd4a641ac88f ("leds: trigger: implement a tty trigger")
Signed-off-by: Marek Behún <kabel@kernel.org>
Link: https://lore.kernel.org/r/20230802090753.13611-1-kabel@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>

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leds: trigger/tty: Use led_set_brightness_sync() from workqueue

led_set_brightness() involves scheduling a workqueue. As here the led's
brightness setting is done in context of the trigger's workque

leds: trigger/tty: Use led_set_brightness_sync() from workqueue

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: fd4a641ac88f ("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>

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leds: trigger: Fix error path to not unlock the unlocked mutex

ttyname is allocated before the mutex is taken, so it must not be
unlocked in the error path.

Fixes: fd4a641ac88f ("leds: trigger: imp

leds: trigger: Fix error path to not unlock the unlocked mutex

ttyname is allocated before the mutex is taken, so it must not be
unlocked in the error path.

Fixes: fd4a641ac88f ("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>

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leds: trigger: implement a tty trigger

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 trigge

leds: trigger: implement a tty trigger

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>

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