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

[Mailing Lists <maillist@superlative.org>]

OK, I will do that.

Quick question: what is the best git I should clone to create patches
against these days? I've been out of the loop for a few years now.

Cheers,

Keith

On Wed, 14 Oct 2020 at 15:00, Takashi Iwai <tiwai@suse.de> wrote:

> On Wed, 14 Oct 2020 15:56:32 +0200,
> Mailing Lists wrote:
> >
> > Yes, and I don't think this is practical (at least, not obviously).
> >
> > The "Roland" vs "BOSS" thing is pure branding. I have BOSS branded
> devices,
> > like the JS-8, which work perfectly without the patch as an example. It
> > wouldn't surprise me if there are recent Roland branded devices which
> require
> > the patch.
> >
> > So I, personally, think it is beyond brand and is device range or
> generation
> > specific. I guess it is possible there may be some technical
> parameter within
> > the device descriptor which could indicate which variant the device is,
> but I
> > don't know what that might be (if at all). At this point I think we
> probably
> > have to apply a conditional setting based on the Product ID.
> >
> > Given that, is it best to continue hacking these into pcm.c, or should
> we be
> > looking at a quirks-table way to describe these?
>
> Currently it's better to grow the explicit allow-list, I suppose.
> Those are still handful, hence manageable enough.
>
> But, we should consider improving search_roland_implicit_fb(), too.
> Both actions don't conflict, and once after we establish the better
> implicit-fb check, the allow-list can be dropped.
>
>
> thanks,
>
> Takashi
>
> >
> > Cheers,
> >
> > Keith
> >
> > On Wed, 14 Oct 2020 at 14:47, Takashi Iwai <tiwai@suse.de> wrote:
> >
> >     On Wed, 14 Oct 2020 15:33:03 +0200,
> >     Mailing Lists wrote:
> >     >
> >     > Thanks for the response Takashi,
> >     >
> >     > How should this be distinguishing between Roland and BOSS? They
> both
> >     have the
> >     > vendor ID 0x0582.
> >
> >     Ah, right, I missed that point :-<
> >
> >     So the question would be rather how to detect BOSS devices
> >     effectively...
> >
> >     thanks,
> >
> >     Takashi
> >
> >     >
> >     > Cheers,
> >     >
> >     > Keith
> >     >
> >     > On Wed, 14 Oct 2020 at 14:09, Takashi Iwai <tiwai@suse.de> wrote:
> >     >
> >     >     On Wed, 14 Oct 2020 14:17:35 +0200,
> >     >     Mailing Lists 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?
> >     >
> >     >     Do we really need this change at all?  I looked at the code
> again,
> >     and
> >     >     I noticed that basically the function should return 0 without
> >     setting
> >     >     anything else even if you don't have the explicit ID checks
> there.
> >     >
> >     >     The function looks like:
> >     >
> >     >     static int set_sync_ep_implicit_fb_quirk(struct
> snd_usb_substream
> >     *subs,
> >     >                                              struct usb_device
> *dev,
> >     >                                              struct
> >     usb_interface_descriptor
> >     >     *altsd,
> >     >                                              unsigned int attr)
> >     >     {
> >     >             ....
> >     >             switch (subs->stream->chip->usb_id) {
> >     >             ....
> >     >             case USB_ID(0x0582, 0x01d8): /* BOSS Katana */
> >     >                     /* BOSS Katana amplifiers do not need quirks */
> >     >                     return 0;
> >     >             }
> >     >
> >     >             if (attr == USB_ENDPOINT_SYNC_ASYNC &&
> >     >                 altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
> >     >                 altsd->bInterfaceProtocol == 2 &&
> >     >                 altsd->bNumEndpoints == 1 &&
> >     >                 USB_ID_VENDOR(subs->stream->chip->usb_id) ==
> 0x0582 /*
> >     Roland
> >     >     */ &&
> >     >                 search_roland_implicit_fb(dev,
> altsd->bInterfaceNumber +
> >     1,
> >     >                                           altsd->bAlternateSetting,
> >     >                                           &alts, &ep) >= 0) {
> >     >                     goto add_sync_ep;
> >     >             }
> >     >
> >     >             /* No quirk */
> >     >             return 0;
> >     >
> >     >     ... and the lengthy if-conditions after the switch/case is
> applied
> >     >     only for Roland devices, hence it shouldn't influence on BOSS
> >     >     devices.  After that point, the immediate return with 0, which
> is
> >     the
> >     >     same as we do in switch/case.  So the explicit check of BOSS
> devices
> >     >     there looks superfluous.
> >     >
> >     >     thanks,
> >     >
> >     >     Takashi
> >     >
> >     > --
> >     > --
> >     > Keith A Milner
> >     >
> >     >
> >
> > --
> > --
> > Keith A Milner
> >
> >
>


-- 
-- 
Keith A Milner