Hi Pavel, On Mon, Aug 23, 2021 at 03:17:11PM +0200, Pavel Hofman wrote: > There is a problem with max packet size calculation for EP-IN. It has been > discussed here recently > https://www.spinics.net/lists/linux-usb/msg214615.html > > The simple change in the post above fixed Win10 enumeration for me and > another tester. I faced the same error on Win10 and also tried the above patch and it worked for me as well. Are you planning to send a formal patch for it? If so, you can add my Tested-by: Jack Pham <jackp@xxxxxxxxxxxxxx> > Also, there is a problem with feedback value calculation which Win10 ignores > and keeps sending the same amount of samples. The fix is to send number of > samples per the actual packet, not per microframe for USB2. I have not > posted the attached patch as the whole patchset will most likely be reverted > for 5.15 https://www.spinics.net/lists/linux-usb/msg216042.html and I wanted > to wait till the situation works out to avoid confusion. In the attached > patch just change the ->c_srate_active to ->c_srate (the patch is on top of > more changes for switching between multiple samplerates). It doesn't look like any of the feedback EP changes got reverted for 5.14 / 5.15-rc1 so it looks like the dust has settled. Are you going to send the below patch formally as well? Thanks! Jack > From 91dda032dd0958006a4e0a6f1f51526cefd95a1e Mon Sep 17 00:00:00 2001 > From: Pavel Hofman <pavel.hofman@xxxxxxxxxxx> > Date: Thu, 12 Aug 2021 18:03:36 +0200 > Subject: [PATCH 9/9] usb: gadget: u_audio: EP-OUT bInterval in fback frequency > > Tests have revealed that Win10 and OSX UAC2 drivers require > the feedback frequency to be based on the actual packet > interval instead of on the USB2 microframe. Otherwise they > ignore the feedback value. Linux snd-usb-audio driver > detects the applied bitshift automatically. > > The patch increases the bitshift in feedback frequency > calculation with EP-OUT bInterval value. > > Signed-off-by: Pavel Hofman <pavel.hofman@xxxxxxxxxxx> > Tested-by: Henrik Enquist <henrik.enquist@xxxxxxxxx> > --- > drivers/usb/gadget/function/u_audio.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c > index a7896fbbab36..c70bdb565153 100644 > --- a/drivers/usb/gadget/function/u_audio.c > +++ b/drivers/usb/gadget/function/u_audio.c > @@ -98,11 +98,13 @@ static const struct snd_pcm_hardware uac_pcm_hardware = { > }; > > static void u_audio_set_fback_frequency(enum usb_device_speed speed, > + struct usb_ep *out_ep, > unsigned long long freq, > unsigned int pitch, > void *buf) > { > u32 ff = 0; > + const struct usb_endpoint_descriptor *ep_desc; > > /* > * Because the pitch base is 1000000, the final divider here > @@ -130,8 +132,13 @@ static void u_audio_set_fback_frequency(enum usb_device_speed speed, > * byte fromat (that is Q16.16) > * > * ff = (freq << 16) / 8000 > + * > + * Win10 and OSX UAC2 drivers require number of samples per packet > + * in order to honor the feedback value. > + * Linux snd-usb-audio detects the used bit shift automatically. > */ > - freq <<= 4; > + ep_desc = out_ep->desc; > + freq <<= 4 + (ep_desc->bInterval - 1); > } > > ff = DIV_ROUND_CLOSEST_ULL((freq * pitch), 1953125); > @@ -263,7 +270,7 @@ static void u_audio_iso_fback_complete(struct usb_ep *ep, > pr_debug("%s: iso_complete status(%d) %d/%d\n", > __func__, status, req->actual, req->length); > > - u_audio_set_fback_frequency(audio_dev->gadget->speed, > + u_audio_set_fback_frequency(audio_dev->gadget->speed, audio_dev->out_ep, > params->c_srate_active, prm->pitch, > req->buf); > > @@ -578,7 +585,7 @@ int u_audio_start_capture(struct g_audio *audio_dev) > * be meauserd at start of playback > */ > prm->pitch = 1000000; > - u_audio_set_fback_frequency(audio_dev->gadget->speed, > + u_audio_set_fback_frequency(audio_dev->gadget->speed, ep, > params->c_srate_active, prm->pitch, > req_fback->buf); > > -- > 2.25.1 > -- The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
