[alsa-devel] [PATCH] ALSA: usb-audio: work around KEF X300A firmware bug

[Takashi Iwai]

At Sun, 16 Feb 2014 17:11:10 +0100,
Clemens Ladisch wrote:
> 
> When the driver tries to access Function Unit 10, the KEF X300A
> speakers' firmware apparently locks up, making even PCM streaming
> impossible.  Work around this by ignoring this FU.
> 
> Cc: <stable at vger.kernel.org>
> Signed-off-by: Clemens Ladisch <clemens at ladisch.de>

Thanks, applied.


Takashi

> ---
>  sound/usb/mixer_maps.c |    9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/sound/usb/mixer_maps.c b/sound/usb/mixer_maps.c
> index 32af6b7..d1d72ff 100644
> --- a/sound/usb/mixer_maps.c
> +++ b/sound/usb/mixer_maps.c
> @@ -328,6 +328,11 @@ static struct usbmix_name_map gamecom780_map[] = {
>  	{}
>  };
> 
> +static const struct usbmix_name_map kef_x300a_map[] = {
> +	{ 10, NULL }, /* firmware locks up (?) when we try to access this FU */
> +	{ 0 }
> +};
> +
>  /*
>   * Control map entries
>   */
> @@ -419,6 +424,10 @@ static struct usbmix_ctl_map usbmix_ctl_maps[] = {
>  		.id = USB_ID(0x200c, 0x1018),
>  		.map = ebox44_map,
>  	},
> +	{
> +		.id = USB_ID(0x27ac, 0x1000),
> +		.map = kef_x300a_map,
> +	},
>  	{ 0 } /* terminator */
>  };
>