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

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

[Daniel Mack]

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@wemgehoertderstaat.de
Original-code-by: Guido Aulisi <guido.aulisi@gmail.com>
Tested-by: Dr Nicholas J Bailey <nicholas.bailey@glasgow.ac.uk>
Signed-off-by: Daniel Mack <zonque@gmail.com>
---
 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

Re: [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@wemgehoertderstaat.de
> Original-code-by: Guido Aulisi <guido.aulisi@gmail.com>
> Tested-by: Dr Nicholas J Bailey <nicholas.bailey@glasgow.ac.uk>
> Signed-off-by: Daniel Mack <zonque@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
> 

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

[Daniel Mack]

On 02.10.2013 15:48, Takashi Iwai wrote:
> 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@wemgehoertderstaat.de
>> Original-code-by: Guido Aulisi <guido.aulisi@gmail.com>
>> Tested-by: Dr Nicholas J Bailey <nicholas.bailey@glasgow.ac.uk>
>> Signed-off-by: Daniel Mack <zonque@gmail.com>
> 
> Why this fixes the issue at all?
> There is no explanation in the thread.

I have no idea of this driver.

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

You're right. I guess, however, that there was a reason to add the code
in the first place.

Anyway, I'll send another patch that does the removal.

Thanks,
Daniel

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

[Guido Aulisi]

Hi,
I saw this thread only today.
if I remember well, that patch worked because the check wrapped around
03ff, but in the end I removed that check totally.
I haven't used my Tascam US122 since may 2013, because I work with an
RME Raydat in my studio and I used the Tascam only for live recording.
If you want, I can do some other testing on my US122.
Ciao
Guido Aulisi


2013/10/2 Daniel Mack <zonque@gmail.com>:
> On 02.10.2013 15:48, Takashi Iwai wrote:
>> 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@wemgehoertderstaat.de
>>> Original-code-by: Guido Aulisi <guido.aulisi@gmail.com>
>>> Tested-by: Dr Nicholas J Bailey <nicholas.bailey@glasgow.ac.uk>
>>> Signed-off-by: Daniel Mack <zonque@gmail.com>
>>
>> Why this fixes the issue at all?
>> There is no explanation in the thread.
>
> I have no idea of this driver.
>
>> If any, the sanity check there is simply bogus for ehci, and it'd be
>> better to get rid of it completely.
>
> You're right. I guess, however, that there was a reason to add the code
> in the first place.
>
> Anyway, I'll send another patch that does the removal.
>
> Thanks,
> Daniel
>

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

[Daniel Mack]

On 03.10.2013 11:59, Guido Aulisi wrote:
> Hi,
> I saw this thread only today.
> if I remember well, that patch worked because the check wrapped around
> 03ff, but in the end I removed that check totally.

That's what the second version of my patch also does.

Next time, when detecting such problems, please consider sending a patch
to alsa-devel, so fixes make it to the users eventually :)


Thanks,
Daniel