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    Subject[PATCH v8 3/3] ledtrig-tty: call correct brightness set function
    Date
    The problem is, however, that with LEDs that are connected directly to
    the SOC via a GPIO, the LED cannot be switched on or off.
    Because the 'leds-gpio' device driver does not need a delayed work.

    If we look at the callstack for the function 'led_set_brightness_sync',
    then at the end it is checked whether the LED device driver has the
    function 'brightness_set_blocking' implemented. This is not the case for
    the 'leds-gpio' device.

    The function 'brightness_set_blocking' returns LED devices -ENOTSUPP.
    This is not evaluated in 'ledtrig-tty' trigger.

    In order for the trigger to also work with LED that does not have the
    'brightness_set_blocking' function implemented, we must therefore use the
    internal API of the LED subsystem and use the function
    'led_set_brightness_nosleep'.

    Signed-off-by: Florian Eckert <fe@dev.tdt.de>
    ---
    drivers/leds/trigger/ledtrig-tty.c | 10 ++++++----
    1 file changed, 6 insertions(+), 4 deletions(-)

    diff --git a/drivers/leds/trigger/ledtrig-tty.c b/drivers/leds/trigger/ledtrig-tty.c
    index d3407830fa69..132e809898a7 100644
    --- a/drivers/leds/trigger/ledtrig-tty.c
    +++ b/drivers/leds/trigger/ledtrig-tty.c
    @@ -7,6 +7,8 @@
    #include <linux/tty.h>
    #include <uapi/linux/serial.h>

    +#include "../leds.h"
    +
    enum tty_led_mode {
    TTY_LED_RXTX,
    TTY_LED_CTS,
    @@ -164,9 +166,9 @@ static void ledtrig_tty_flags(struct ledtrig_tty_data *trigger_data, unsigned in

    status = tty_get_mget(trigger_data->tty);
    if (status & flag)
    - led_set_brightness_sync(trigger_data->led_cdev, LED_ON);
    + led_set_brightness_nosleep(trigger_data->led_cdev, LED_ON);
    else
    - led_set_brightness_sync(trigger_data->led_cdev, LED_OFF);
    + led_set_brightness_nosleep(trigger_data->led_cdev, LED_OFF);
    }

    static void ledtrig_tty_work(struct work_struct *work)
    @@ -229,12 +231,12 @@ static void ledtrig_tty_work(struct work_struct *work)
    }

    if (icount.rx != trigger_data->rx || icount.tx != trigger_data->tx) {
    - led_set_brightness_sync(trigger_data->led_cdev, LED_ON);
    + led_set_brightness_nosleep(trigger_data->led_cdev, LED_ON);

    trigger_data->rx = icount.rx;
    trigger_data->tx = icount.tx;
    } else {
    - led_set_brightness_sync(trigger_data->led_cdev, LED_OFF);
    + led_set_brightness_nosleep(trigger_data->led_cdev, LED_OFF);
    }
    break;
    }
    --
    2.30.2
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