[PATCH 1/3] HID: elan: Silence mute LED errors being logged when the device is unplugged

[PATCH 1/3] HID: elan: Silence mute LED errors being logged when the device is unplugged

[Hans de Goede]

Being integrated into an USB keyboard-dock the mute LED can go away
at any time, leading to the following errors:

[  918.667671] elan 0003:04F3:0755.0002: Failed to set mute led brightness: -19
[  918.667737] leds elan:red:mute: Setting an LED's brightness failed (-19)

Fix this by making the following changes:

1. Don't log an error from elan_mute_led_set_brigtness() when ret == ENODEV
2. Set the LED_HW_PLUGGABLE flag on the mute LED led_classdev

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/hid/hid-elan.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-elan.c b/drivers/hid/hid-elan.c
index dae193749d44..71740988a3f6 100644
--- a/drivers/hid/hid-elan.c
+++ b/drivers/hid/hid-elan.c
@@ -445,7 +445,8 @@ static int elan_mute_led_set_brigtness(struct led_classdev *led_cdev,
 	kfree(dmabuf);
 
 	if (ret != ELAN_LED_REPORT_SIZE) {
-		hid_err(hdev, "Failed to set mute led brightness: %d\n", ret);
+		if (ret != -ENODEV)
+			hid_err(hdev, "Failed to set mute led brightness: %d\n", ret);
 		return ret;
 	}
 
@@ -462,6 +463,7 @@ static int elan_init_mute_led(struct hid_device *hdev)
 	mute_led->brightness_get = elan_mute_led_get_brigtness;
 	mute_led->brightness_set_blocking = elan_mute_led_set_brigtness;
 	mute_led->max_brightness = LED_ON;
+	mute_led->flags = LED_HW_PLUGGABLE;
 	mute_led->dev = &hdev->dev;
 
 	return devm_led_classdev_register(&hdev->dev, mute_led);
-- 
2.30.1

[PATCH 2/3] HID: elan: Set default_trigger-s for the mute LED

[Hans de Goede]

The mute LED should be automatically turned on/off based
on the audio-cards mixer settings.

Add the standardized default-trigger name for this, so that the alsa
code can turn the LED on/off as appropriate (on supported audio cards).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/hid/hid-elan.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/hid/hid-elan.c b/drivers/hid/hid-elan.c
index 71740988a3f6..6958649ece22 100644
--- a/drivers/hid/hid-elan.c
+++ b/drivers/hid/hid-elan.c
@@ -460,6 +460,7 @@ static int elan_init_mute_led(struct hid_device *hdev)
 	struct led_classdev *mute_led = &drvdata->mute_led;
 
 	mute_led->name = "elan:red:mute";
+	mute_led->default_trigger = "audio-mute";
 	mute_led->brightness_get = elan_mute_led_get_brigtness;
 	mute_led->brightness_set_blocking = elan_mute_led_set_brigtness;
 	mute_led->max_brightness = LED_ON;
-- 
2.30.1

Re: [PATCH 2/3] HID: elan: Set default_trigger-s for the mute LED

[Marek Behún]

Again I would use
  ... Set default_triggers for ...

Reviewed-by: Marek Behún <kabel@kernel.org>

[PATCH 3/3] HID: elan: Remove elan_mute_led_get_brigtness()

[Hans de Goede]

The led_classdev already contains a cached value of the last set
brightness, the brightness_get callback is only meant for LED drivers
which can read back the actual / current brightness from the hardware.

Since elan_mute_led_get_brigtness() just returns the last set value
it does not add any functionality, so we can just remove it.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/hid/hid-elan.c | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/drivers/hid/hid-elan.c b/drivers/hid/hid-elan.c
index 6958649ece22..f1ac0443ee67 100644
--- a/drivers/hid/hid-elan.c
+++ b/drivers/hid/hid-elan.c
@@ -410,15 +410,6 @@ static int elan_start_multitouch(struct hid_device *hdev)
 	return 0;
 }
 
-static enum led_brightness elan_mute_led_get_brigtness(struct led_classdev *led_cdev)
-{
-	struct device *dev = led_cdev->dev->parent;
-	struct hid_device *hdev = to_hid_device(dev);
-	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
-
-	return drvdata->mute_led_state;
-}
-
 static int elan_mute_led_set_brigtness(struct led_classdev *led_cdev,
 				       enum led_brightness value)
 {
@@ -461,7 +452,6 @@ static int elan_init_mute_led(struct hid_device *hdev)
 
 	mute_led->name = "elan:red:mute";
 	mute_led->default_trigger = "audio-mute";
-	mute_led->brightness_get = elan_mute_led_get_brigtness;
 	mute_led->brightness_set_blocking = elan_mute_led_set_brigtness;
 	mute_led->max_brightness = LED_ON;
 	mute_led->flags = LED_HW_PLUGGABLE;
-- 
2.30.1

Re: [PATCH 3/3] HID: elan: Remove elan_mute_led_get_brigtness()

[Marek Behún]

Reviewed-by: Marek Behún <kabel@kernel.org>

Re: [PATCH 1/3] HID: elan: Silence mute LED errors being logged when the device is unplugged

[Marek Behún]

On Sat, 20 Feb 2021 17:32:09 +0100
Hans de Goede <hdegoede@redhat.com> wrote:

> 1. Don't log an error from elan_mute_led_set_brigtness() when ret == ENODEV
ret == -ENODEV

Otherwise
Reviewed-by: Marek Behún <kabel@kernel.org>