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@xxxxxxxxxx>
---
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
