From 4d76235fe3484e46f4746dbb1cc55712401b7beb Mon Sep 17 00:00:00 2001 From: Hans Petter Selasky Date: Wed, 19 Oct 2016 18:45:06 +0000 Subject: [PATCH] Add support for adjusting the hardware buffering delay for USB audio. Requested by: Goran Mekic MFC after: 1 week --- sys/dev/sound/usb/uaudio.c | 35 ++++++++++++++++++++++++++++++----- 1 file changed, 30 insertions(+), 5 deletions(-) diff --git a/sys/dev/sound/usb/uaudio.c b/sys/dev/sound/usb/uaudio.c index 3de87ae7185c..7e32b706c2d7 100644 --- a/sys/dev/sound/usb/uaudio.c +++ b/sys/dev/sound/usb/uaudio.c @@ -95,6 +95,7 @@ __FBSDID("$FreeBSD$"); static int uaudio_default_rate = 0; /* use rate list */ static int uaudio_default_bits = 32; static int uaudio_default_channels = 0; /* use default */ +static int uaudio_buffer_ms = 8; #ifdef USB_DEBUG static int uaudio_debug = 0; @@ -109,9 +110,32 @@ SYSCTL_INT(_hw_usb_uaudio, OID_AUTO, default_bits, CTLFLAG_RWTUN, &uaudio_default_bits, 0, "uaudio default sample bits"); SYSCTL_INT(_hw_usb_uaudio, OID_AUTO, default_channels, CTLFLAG_RWTUN, &uaudio_default_channels, 0, "uaudio default sample channels"); + +static int +uaudio_buffer_ms_sysctl(SYSCTL_HANDLER_ARGS) +{ + int err, val; + + val = uaudio_buffer_ms; + err = sysctl_handle_int(oidp, &val, 0, req); + + if (err != 0 || req->newptr == NULL || val == uaudio_buffer_ms) + return (err); + + if (val > 8) + val = 8; + else if (val < 2) + val = 2; + + uaudio_buffer_ms = val; + + return (0); +} +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"); #endif -#define UAUDIO_IRQS (8000 / UAUDIO_NFRAMES) /* interrupts per second */ #define UAUDIO_NFRAMES 64 /* must be factor of 8 due HS-USB */ #define UAUDIO_NCHANBUFS 2 /* number of outstanding request */ #define UAUDIO_RECURSE_LIMIT 255 /* rounds */ @@ -1278,10 +1302,10 @@ uaudio_configure_msg_sub(struct uaudio_softc *sc, if (fps < 8000) { /* FULL speed USB */ - frames = 8; + frames = uaudio_buffer_ms; } else { /* HIGH speed USB */ - frames = UAUDIO_NFRAMES; + frames = uaudio_buffer_ms * 8; } fps_shift = usbd_xfer_get_fps_shift(chan->xfer[0]); @@ -2158,8 +2182,9 @@ tr_setup: } /* start the SYNC transfer one time per second, if any */ - if (++(ch->intr_counter) >= UAUDIO_IRQS) { - ch->intr_counter = 0; + ch->intr_counter += ch->intr_frames; + if (ch->intr_counter >= ch->frames_per_second) { + ch->intr_counter -= ch->frames_per_second; usbd_transfer_start(ch->xfer[UAUDIO_NCHANBUFS]); }