On Tue, 07 Jul 2020 12:03:25 +0200, Pavel Hofman wrote: > > Hi Takashi, > > Dne 07. 07. 20 v 11:40 Takashi Iwai napsal(a): > > On Fri, 03 Jul 2020 12:17:14 +0200, > > Pavel Hofman wrote: > >> > >> > >> Dne 02. 07. 20 v 13:28 Pavel Hofman napsal(a): > >>> > >>> > >>> Please is the requirement that EP OUT + EP IN implicit feedback data > >>> must be in the same interface really necessary? If such a requirement > >>> was dropped, IMO many devices could be removed from the existing > >>> set_sync_ep_implicit_fb_quirk and many devices would work out of the > >>> box, > >> > >> I am still thinking about the single-interface requirement. If both > >> endpoints were to be part of a single interface, could they use > >> different altsettings for different sample lengths for capture and > >> playback? E.g. to save USB bandwidth when the capture is used only for > >> implicit feedback - capturing at 16bits, playback at 32bits. > >> > >> In the quirked XMOS devices the common clock for both directions is > >> defined by the clock feature, the altsettings for each direction (in > >> separate interfaces) are used for setting sample length. > > > > Could you check for-linus branch of my sound git tree? > > Just to be sure whether you're hitting the issue that has been already > > addressed. > > > > I developed the RTX6001 patch on 5.8-rc3 kernel, and commits since > that tag in > https://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git/log/?h=for-linus > do not seem to address the issue. > > I think the generic code searching for the implicit-feedback endpoint > works only on the current interface (alts) > https://github.com/tiwai/sound/blob/master/sound/usb/pcm.c#L491 > > I do not know if searching for IN endpoints with the same number and > USB_ENDPOINT_USAGE_IMPLICIT_FB mask in other interfaces is > correct. But it seems to me it would yield correct results for a > number of existing quirks in set_sync_ep_implicit_fb_quirk (typically > those setting ep=0x81). Yeah I found your patch later. Now it's in for-linus branch, too. Takashi
