When I tried this change earlier this year on the BOSS GT-1, it enabled sound output on the card (which was not previously working), but with significant issues. It resulted in frequent pops and crackles - presumably because of the loss of synchronization using implicit feedback. This was the fix that ended up working for me: https://mailman.alsa-project.org/pipermail/alsa-devel/2020-January/161951.html But maybe something else has changed in the handling of implicit feedback since then? Mike On Wed, Oct 14, 2020 at 5:17 AM Mailing Lists <maillist@xxxxxxxxxxxxxxx> wrote: > 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 >
