RE: [PATCH] V2: platform/x86: dell-laptop: don't register platform::micmute if the related tokens don't exist.

[Mario.Limonciello]

> -----Original Message-----
> From: koba.ko@xxxxxxxxxxxxx <koba.ko@xxxxxxxxxxxxx>
> Sent: Sunday, May 10, 2020 8:45 PM
> To: Matthew Garrett; Pali Rohár; Darren Hart; Andy Shevchenko; platform-driver-
> x86@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Limonciello, Mario
> Subject: [PATCH] V2: platform/x86: dell-laptop: don't register
> platform::micmute if the related tokens don't exist.
> 
> 
> [EXTERNAL EMAIL]
> 
> From: Koba Ko <koba.ko@xxxxxxxxxxxxx>
> 
> On dell G3-3590, 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@xxxxxxxxxxxxx>
> ---
> Changelog:
> 1. Refine the typo of comment.
> ---
>  drivers/platform/x86/dell-laptop.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-
> laptop.c
> index 1e46022fb2c5..afc1ded83e56 100644
> --- a/drivers/platform/x86/dell-laptop.c
> +++ b/drivers/platform/x86/dell-laptop.c
> @@ -2208,10 +2208,13 @@ 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;
> +	}
> 
>  	if (acpi_video_get_backlight_type() != acpi_backlight_vendor)
>  		return 0;
> --
> 2.17.1

Reviewed-by: Mario Limonciello <Mario.limonciello@xxxxxxxx>