[PATCH v2 1/1][SRU][OEM-OSP1-B] UBUNTU: SAUCE: platform/x86: dell-laptop: don't register platform::micmute if the related tokens don't exist

[Koba Ko]

BugLink: https://bugs.launchpad.net/bugs/1877275

Error message is issued during boot up,
"platform::micmute: Setting an LED's brightness failed (-19)",
but there's no micmute led on the machine.

Get the related tokens of SMBIOS, GLOBAL_MIC_MUTE_DISABLE/ENABLE.
If one of two tokens doesn't exist,
don't call led_classdev_register() for platform::micmute.
After that, you wouldn't see the platform::micmute in /sys/class/leds/,
and the error message wouldn't see in dmesg.

Signed-off-by: Koba Ko <koba.ko at canonical.com>
---
 drivers/platform/x86/dell-laptop.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
index 1e46022fb2c5..53175bdfe166 100644
--- a/drivers/platform/x86/dell-laptop.c
+++ b/drivers/platform/x86/dell-laptop.c
@@ -2167,7 +2167,7 @@ static struct led_classdev micmute_led_cdev = {
 static int __init dell_init(void)
 {
 	struct calling_interface_token *token;
-	int max_intensity = 0;
+	int max_intensity = 0, micmute_exists = 0;
 	int ret;
 
 	if (!dmi_check_system(dell_device_table))
@@ -2208,10 +2208,14 @@ static int __init dell_init(void)
 
 	dell_laptop_register_notifier(&dell_laptop_notifier);
 
-	micmute_led_cdev.brightness = ledtrig_audio_get(LED_AUDIO_MICMUTE);
-	ret = led_classdev_register(&platform_device->dev, &micmute_led_cdev);
-	if (ret < 0)
-		goto fail_led;
+	if (dell_smbios_find_token(GLOBAL_MIC_MUTE_DISABLE) &&
+	    dell_smbios_find_token(GLOBAL_MIC_MUTE_ENABLE)) {
+		micmute_led_cdev.brightness = ledtrig_audio_get(LED_AUDIO_MICMUTE);
+		ret = led_classdev_register(&platform_device->dev, &micmute_led_cdev);
+		if (ret < 0)
+			goto fail_led;
+		micmute_exists = 1;
+	}
 
 	if (acpi_video_get_backlight_type() != acpi_backlight_vendor)
 		return 0;
@@ -2258,7 +2262,8 @@ static int __init dell_init(void)
 fail_get_brightness:
 	backlight_device_unregister(dell_backlight_device);
 fail_backlight:
-	led_classdev_unregister(&micmute_led_cdev);
+	if (micmute_exists)
+		led_classdev_unregister(&micmute_led_cdev);
 fail_led:
 	dell_cleanup_rfkill();
 fail_rfkill:
-- 
2.17.1