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@xxxxxxx> 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@xxxxxxxxx> > > 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 > > > _______________________________________________ > Alsa-devel mailing list > Alsa-devel@xxxxxxxxxxxxxxxx > https://mailman.alsa-project.org/mailman/listinfo/alsa-devel > -- -- Keith A Milner