};
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
* 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 applied bit-shift automatically.
*/
- freq <<= 4;
+ ep_desc = out_ep->desc;
+ freq <<= 4 + (ep_desc->bInterval - 1);
}
ff = DIV_ROUND_CLOSEST_ULL((freq * pitch), 1953125);
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, prm->pitch,
req->buf);
* 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, prm->pitch,
req_fback->buf);