[V2] usbcore: Select UAC3 configuration for audio if present

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, Sep 12, 2018 at 01:03:57AM +0530, saranya.gopal@intel.com wrote:
> From: Saranya Gopal <saranya.gopal@intel.com>

Any reason you forgot to cc: the usb maintainer?  :)

> 
> USB audio class 3.0 specification introduced many significant
> changes like
>  - new power domains, support for LPM/L1
>  - new cluster descriptor
>  - new high capability and class-specific string descriptors
>  - BADD profiles
>  - ... and many other things (check spec from link below:
> http://www.usb.org/developers/docs/devclass_docs/USB_Audio_v3.0.zip)
> 
> Now that UAC3 is supported in linux, choose UAC3
> configuration for audio if the device supports it.
> Selecting this configuration will enable the system to
> save power by leveraging the new power domains and LPM L1
> capability and also support new codec types and data formats
> for consumer audio applications.
> 
> Signed-off-by: Saranya Gopal <saranya.gopal@intel.com>
> Reviewed-by: Felipe Balbi <felipe.balbi@linux.intel.com>
> ---
> Changes from V1: Deleted nested if check for is_uac3_config
> 
>  drivers/usb/core/generic.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c
> index bc8242b..df38d5a 100644
> --- a/drivers/usb/core/generic.c
> +++ b/drivers/usb/core/generic.c
> @@ -21,6 +21,7 @@
>  
>  #include <linux/usb.h>
>  #include <linux/usb/hcd.h>
> +#include <uapi/linux/usb/audio.h>
>  #include "usb.h"
>  
>  static inline const char *plural(int n)
> @@ -42,6 +43,16 @@ static int is_activesync(struct usb_interface_descriptor *desc)
>  		&& desc->bInterfaceProtocol == 1;
>  }
>  
> +static int is_audio(struct usb_interface_descriptor *desc)

bool?

> +{
> +	return desc->bInterfaceClass == USB_CLASS_AUDIO;
> +}
> +
> +static int is_uac3_config(struct usb_interface_descriptor *desc)

bool?

thanks,

greg k-h