Re: [alsa-devel] [PATCH] ALSA: usb-audio: Disable quirks for BOSS Katana amplifiers

From: Mailing Lists <maillist@superlative.org>
To: alsa-devel@alsa-project.org
Cc: Takashi Iwai <tiwai@suse.de>, Mike Oliphant <oliphant@nostatic.org>
Subject: Re: [alsa-devel] [PATCH] ALSA: usb-audio: Disable quirks for BOSS Katana amplifiers
Date: Wed, 14 Oct 2020 13:17:35 +0100	[thread overview]
Message-ID: <CAPMdQDmY7CdbrHyOwhJNFBREQ0EO1SKufRdN_YR6TG4zmJzXpA@mail.gmail.com> (raw)
In-Reply-To: <s5hftjriy1q.wl-tiwai@suse.de>

Following up on this, it appears there are a bunch of the newer-generation
Roland/Boss devices which need similar treatment.

So far I have tested the GT-1, the GT-001, and the BR-80, and others have
reported the RC-300 as working with similar modifications. I have been
using the following change to the code in pcm.c
set_sync_ep_implicit_fb_quirk:

    case USB_ID(0x0582, 0x01d8): /* BOSS Katana */
    case USB_ID(0x0582, 0x0130): /* BOSS Micro BR-80 */
    case USB_ID(0x0582, 0x0138): /* BOSS RC-300 */
    case USB_ID(0x0582, 0x01d6): /* BOSS GT-1 */
    case USB_ID(0x0582, 0x01e5): /* BOSS GT-001 */
/* BOSS Katana amplifiers and many other newer BOSS devices do not need
quirks */

There's probably others too, such as the GT-100 (I believe the GT-001 and
GT-100 have similar hardware).

My question is, should this just be submitted as a patch to pcm.c or would
it be better handled in quirks and, if so, how?

Or something else?

Personally, I dislike the approach of hard-coding exceptions into core code
as it seems that's what quirks are there for, but there seems to be a whole
bunch of exceptions in there already.

Cheers,

Keith

On Thu, 17 Oct 2019 at 09:20, Takashi Iwai <tiwai@suse.de> wrote:

> On Fri, 11 Oct 2019 19:19:36 +0200,
> Szabolcs Szőke wrote:
> >
> > BOSS Katana amplifiers cannot be used for recording or playback if quirks
> > are applied
> >
> > BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=195223
> > Signed-off-by: Szabolcs Szőke <szszoke.code@gmail.com>
>
> Applied now.  Thanks.
>
>
> Takashi
>
> >
> > ---
> >  sound/usb/pcm.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
> > index 33cd26763c0e..daadb0c66eee 100644
> > --- a/sound/usb/pcm.c
> > +++ b/sound/usb/pcm.c
> > @@ -348,6 +348,9 @@ static int set_sync_ep_implicit_fb_quirk(struct
> snd_usb_substream *subs,
> >               ep = 0x84;
> >               ifnum = 0;
> >               goto add_sync_ep_from_ifnum;
> > +     case USB_ID(0x0582, 0x01d8): /* BOSS Katana */
> > +             /* BOSS Katana amplifiers do not need quirks */
> > +             return 0;
> >       }
> >
> >       if (attr == USB_ENDPOINT_SYNC_ASYNC &&
> > --
> > 2.20.1
> >
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>

-- 
-- 
Keith A Milner