leds: trigger: netdev: Skip setting baseline state in activate if hw-controlled

The current codes uses the sw_control path in set_baseline_state() when
called from netdev_trig_activate() even if we're hw-controlled. This
may result in errors when led_set_brightness() is called because we may
not have set_brightness led ops (if hw doesn't support setting a "LED"
to ON). In addition this path may schedule trigger_data->work which
doesn't make sense when being hw-controlled.

Therefore set trigger_data->hw_control = true before calling
set_device_name() from netdev_trig_activate(). In this call chain we
have to prevent set_baseline_state() from being called, because this
would call hw_control_set(). Use led_cdev->trigger_data == NULL as
indicator for being called from netdev_trig_activate().

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/d3f2859c-2673-401c-a4f7-fcaef2167991@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>

diff --git a/drivers/leds/trigger/ledtrig-netdev.c b/drivers/leds/trigger/ledtrig-netdev.c
index 8e5475819590e056142dae6ac1dd8c0dbe186d84..1a0cfbba597638032b9b4bc7af06649f0881099b 100644 (file)
--- a/drivers/leds/trigger/ledtrig-netdev.c
+++ b/drivers/leds/trigger/ledtrig-netdev.c
@@ -277,7 +277,10 @@ static int set_device_name(struct led_netdev_data *trigger_data,
 
        trigger_data->last_activity = 0;
 
-       set_baseline_state(trigger_data);
+       /* Skip if we're called from netdev_trig_activate() and hw_control is true */
+       if (!trigger_data->hw_control || led_get_trigger_data(trigger_data->led_cdev))
+               set_baseline_state(trigger_data);
+
        mutex_unlock(&trigger_data->lock);
        rtnl_unlock();
 
@@ -617,8 +620,8 @@ static int netdev_trig_activate(struct led_classdev *led_cdev)
                if (dev) {
                        const char *name = dev_name(dev);
 
-                       set_device_name(trigger_data, name, strlen(name));
                        trigger_data->hw_control = true;
+                       set_device_name(trigger_data, name, strlen(name));
 
                        rc = led_cdev->hw_control_get(led_cdev, &mode);
                        if (!rc)