Re: [PATCH v10 3/3] leds: trigger: implement a tty trigger

From: Greg Kroah-Hartman
Date: Wed Jan 13 2021 - 11:15:37 EST


On Fri, Dec 18, 2020 at 11:42:46AM +0100, Uwe Kleine-König wrote:
> 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@xxxxxxxxxxxxxx>
> ---
> .../ABI/testing/sysfs-class-led-trigger-tty | 6 +
> drivers/leds/trigger/Kconfig | 9 +
> drivers/leds/trigger/Makefile | 1 +
> drivers/leds/trigger/ledtrig-tty.c | 188 ++++++++++++++++++
> 4 files changed, 204 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-class-led-trigger-tty
> create mode 100644 drivers/leds/trigger/ledtrig-tty.c
>
> diff --git a/Documentation/ABI/testing/sysfs-class-led-trigger-tty b/Documentation/ABI/testing/sysfs-class-led-trigger-tty
> new file mode 100644
> index 000000000000..2bf6b24e781b
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-class-led-trigger-tty
> @@ -0,0 +1,6 @@
> +What: /sys/class/leds/<led>/ttyname
> +Date: Dec 2020
> +KernelVersion: 5.10
> +Contact: linux-leds@xxxxxxxxxxxxxxx
> +Description:
> + Specifies the tty device name of the triggering tty
> diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig
> index ce9429ca6dde..b77a01bd27f4 100644
> --- a/drivers/leds/trigger/Kconfig
> +++ b/drivers/leds/trigger/Kconfig
> @@ -144,4 +144,13 @@ config LEDS_TRIGGER_AUDIO
> the audio mute and mic-mute changes.
> If unsure, say N
>
> +config LEDS_TRIGGER_TTY
> + tristate "LED Trigger for TTY devices"
> + depends on TTY
> + help
> + This allows LEDs to be controlled by activity on ttys which includes
> + serial devices like /dev/ttyS0.
> +
> + When build as a module this driver will be called ledtrig-tty.
> +
> endif # LEDS_TRIGGERS
> diff --git a/drivers/leds/trigger/Makefile b/drivers/leds/trigger/Makefile
> index 733a83e2a718..25c4db97cdd4 100644
> --- a/drivers/leds/trigger/Makefile
> +++ b/drivers/leds/trigger/Makefile
> @@ -15,3 +15,4 @@ obj-$(CONFIG_LEDS_TRIGGER_PANIC) += ledtrig-panic.o
> obj-$(CONFIG_LEDS_TRIGGER_NETDEV) += ledtrig-netdev.o
> obj-$(CONFIG_LEDS_TRIGGER_PATTERN) += ledtrig-pattern.o
> obj-$(CONFIG_LEDS_TRIGGER_AUDIO) += ledtrig-audio.o
> +obj-$(CONFIG_LEDS_TRIGGER_TTY) += ledtrig-tty.o
> diff --git a/drivers/leds/trigger/ledtrig-tty.c b/drivers/leds/trigger/ledtrig-tty.c
> new file mode 100644
> index 000000000000..c1e87c0d23c3
> --- /dev/null
> +++ b/drivers/leds/trigger/ledtrig-tty.c
> @@ -0,0 +1,188 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <linux/delay.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/tty.h>
> +#include <uapi/linux/serial.h>
> +
> +struct ledtrig_tty_data {
> + struct led_classdev *led_cdev;
> + struct delayed_work dwork;
> + struct mutex mutex;
> + const char *ttyname;
> + struct tty_struct *tty;
> + int rx, tx;
> +};
> +
> +static void ledtrig_tty_halt(struct ledtrig_tty_data *trigger_data)
> +{
> + cancel_delayed_work_sync(&trigger_data->dwork);
> +}

This causes the following build warning with the patch applied:

drivers/leds/trigger/ledtrig-tty.c:19:13: warning: ‘ledtrig_tty_halt’ defined but not used [-Wunused-function]
19 | static void ledtrig_tty_halt(struct ledtrig_tty_data *trigger_data)
| ^~~~~~~~~~~~~~~~

Can you fix this up and just resend this patch (the other 2 are already
in my tree), so that I can queue it up?

thanks,

greg k-h