Don't read the USB audio sync endpoint when we don't use it to save

isochronous bandwidth.

MFC after:		3 days
Sponsored by:		Mellanox Technologies
This commit is contained in:
Hans Petter Selasky 2018-11-08 12:46:47 +00:00
parent 5e0e7e1846
commit fb8a716d28

View File

@ -100,7 +100,7 @@ static int uaudio_default_channels = 0; /* use default */
static int uaudio_buffer_ms = 8;
#ifdef USB_DEBUG
static int uaudio_debug = 0;
static int uaudio_debug;
static SYSCTL_NODE(_hw_usb, OID_AUTO, uaudio, CTLFLAG_RW, 0, "USB uaudio");
@ -136,6 +136,8 @@ uaudio_buffer_ms_sysctl(SYSCTL_HANDLER_ARGS)
SYSCTL_PROC(_hw_usb_uaudio, OID_AUTO, buffer_ms, CTLTYPE_INT | CTLFLAG_RWTUN,
0, sizeof(int), uaudio_buffer_ms_sysctl, "I",
"uaudio buffering delay from 2ms to 8ms");
#else
#define uaudio_debug 0
#endif
#define UAUDIO_NFRAMES 64 /* must be factor of 8 due HS-USB */
@ -2161,6 +2163,14 @@ uaudio_chan_play_sync_callback(struct usb_xfer *xfer, usb_error_t error)
break;
case USB_ST_SETUP:
/*
* Check if the recording stream can be used as a
* source of jitter information to save some
* isochronous bandwidth:
*/
if (ch->priv_sc->sc_rec_chan.num_alt != 0 &&
uaudio_debug == 0)
break;
usbd_xfer_set_frames(xfer, 1);
usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_framelen(xfer));
usbd_transfer_submit(xfer);