[alsa-devel] [PATCH] ALSA: snd-usb-usx2y: fix start frame mask

[Takashi Iwai]

At Wed,  2 Oct 2013 15:39:57 +0200,
Daniel Mack wrote:
> 
> This patch is based on a change proposed by Guido Aulisi in a
> discussion on LAU which can be followed here:
> 
>   http://linuxaudio.org/mailarchive/lau/2013/5/20/200177
> 
> Cc: fzu at wemgehoertderstaat.de
> Original-code-by: Guido Aulisi <guido.aulisi at gmail.com>
> Tested-by: Dr Nicholas J Bailey <nicholas.bailey at glasgow.ac.uk>
> Signed-off-by: Daniel Mack <zonque at gmail.com>

Why this fixes the issue at all?
There is no explanation in the thread.

If any, the sanity check there is simply bogus for ehci, and it'd be
better to get rid of it completely.


thanks,

Takashi

> ---
>  sound/usb/usx2y/usbusx2yaudio.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/sound/usb/usx2y/usbusx2yaudio.c b/sound/usb/usx2y/usbusx2yaudio.c
> index 63fb521..cd16fcc 100644
> --- a/sound/usb/usx2y/usbusx2yaudio.c
> +++ b/sound/usb/usx2y/usbusx2yaudio.c
> @@ -328,7 +328,7 @@ static void i_usX2Y_urb_complete(struct urb *urb)
>  		usX2Y_error_urb_status(usX2Y, subs, urb);
>  		return;
>  	}
> -	if (likely((urb->start_frame & 0xFFFF) == (usX2Y->wait_iso_frame & 0xFFFF)))
> +	if (likely((urb->start_frame & 0x03FF) == (usX2Y->wait_iso_frame & 0x03FF)))
>  		subs->completed_urb = urb;
>  	else {
>  		usX2Y_error_sequence(usX2Y, subs, urb);
> -- 
> 1.8.3.1
>