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authorKarsten Wiese <fzu@wemgehoertderstaat.de>2008-07-30 15:13:29 +0200
committerJaroslav Kysela <perex@perex.cz>2008-08-01 13:37:12 +0200
commit030a07e441296c372f946cd4065b5d831d8dc40c (patch)
tree4032eba646f9bf1c6f146adc40b449cf50b59a47 /sound/usb/usx2y/usb_stream.c
parent896e6cc20e67038af12e1a7711eef32647e62f23 (diff)
downloadlinux-linaro-030a07e441296c372f946cd4065b5d831d8dc40c.tar.gz
ALSA: Add USB US122L driver
Added a new US122L usb-audio driver. This driver works together with a dedicated alsa-lib plugin. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Diffstat (limited to 'sound/usb/usx2y/usb_stream.c')
-rw-r--r--sound/usb/usx2y/usb_stream.c761
1 files changed, 761 insertions, 0 deletions
diff --git a/sound/usb/usx2y/usb_stream.c b/sound/usb/usx2y/usb_stream.c
new file mode 100644
index 00000000000..ff23cc1ce3b
--- /dev/null
+++ b/sound/usb/usx2y/usb_stream.c
@@ -0,0 +1,761 @@
+/*
+ * Copyright (C) 2007, 2008 Karsten Wiese <fzu@wemgehoertderstaat.de>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/usb.h>
+
+#include "usb_stream.h"
+
+
+/* setup */
+
+static unsigned usb_stream_next_packet_size(struct usb_stream_kernel *sk)
+{
+ struct usb_stream *s = sk->s;
+ sk->out_phase_peeked = (sk->out_phase & 0xffff) + sk->freqn;
+ return (sk->out_phase_peeked >> 16) * s->cfg.frame_size;
+}
+
+static void playback_prep_freqn(struct usb_stream_kernel *sk, struct urb *urb)
+{
+ struct usb_stream *s = sk->s;
+ unsigned l = 0;
+ int pack;
+
+ urb->iso_frame_desc[0].offset = 0;
+ urb->iso_frame_desc[0].length = usb_stream_next_packet_size(sk);
+ sk->out_phase = sk->out_phase_peeked;
+ urb->transfer_buffer_length = urb->iso_frame_desc[0].length;
+
+ for (pack = 1; pack < sk->n_o_ps; pack++) {
+ l = usb_stream_next_packet_size(sk);
+ if (s->idle_outsize + urb->transfer_buffer_length + l >
+ s->period_size)
+ goto check;
+
+ sk->out_phase = sk->out_phase_peeked;
+ urb->iso_frame_desc[pack].offset = urb->transfer_buffer_length;
+ urb->iso_frame_desc[pack].length = l;
+ urb->transfer_buffer_length += l;
+ }
+ snd_printdd(KERN_DEBUG "%i\n", urb->transfer_buffer_length);
+
+check:
+ urb->number_of_packets = pack;
+ s->idle_outsize += urb->transfer_buffer_length - s->period_size;
+ snd_printdd(KERN_DEBUG "idle=%i ul=%i ps=%i\n", s->idle_outsize,
+ urb->transfer_buffer_length, s->period_size);
+}
+
+static void init_pipe_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
+ struct urb **urbs, char *transfer,
+ struct usb_device *dev, int pipe)
+{
+ int u, p;
+ int maxpacket = use_packsize ?
+ use_packsize : usb_maxpacket(dev, pipe, usb_pipeout(pipe));
+ int transfer_length = maxpacket * sk->n_o_ps;
+
+ for (u = 0; u < USB_STREAM_NURBS;
+ ++u, transfer += transfer_length) {
+ struct urb *urb = urbs[u];
+ struct usb_iso_packet_descriptor *desc;
+ urb->transfer_flags = URB_ISO_ASAP;
+ urb->transfer_buffer = transfer;
+ urb->dev = dev;
+ urb->pipe = pipe;
+ urb->number_of_packets = sk->n_o_ps;
+ urb->context = sk;
+ urb->interval = 1;
+ if (usb_pipeout(pipe))
+ continue;
+
+ urb->transfer_buffer_length = transfer_length;
+ desc = urb->iso_frame_desc;
+ desc->offset = 0;
+ desc->length = maxpacket;
+ for (p = 1; p < sk->n_o_ps; ++p) {
+ desc[p].offset = desc[p - 1].offset + maxpacket;
+ desc[p].length = maxpacket;
+ }
+ }
+}
+
+static void init_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
+ struct usb_device *dev, int in_pipe, int out_pipe)
+{
+ struct usb_stream *s = sk->s;
+ char *indata = (char *)s + sizeof(*s) +
+ sizeof(struct usb_stream_packet) *
+ s->inpackets;
+ int u;
+
+ for (u = 0; u < USB_STREAM_NURBS; ++u) {
+ sk->inurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
+ sk->outurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
+ }
+
+ init_pipe_urbs(sk, use_packsize, sk->inurb, indata, dev, in_pipe);
+ init_pipe_urbs(sk, use_packsize, sk->outurb, sk->write_page, dev,
+ out_pipe);
+}
+
+
+/*
+ * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
+ * this will overflow at approx 524 kHz
+ */
+static inline unsigned get_usb_full_speed_rate(unsigned rate)
+{
+ return ((rate << 13) + 62) / 125;
+}
+
+/*
+ * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
+ * this will overflow at approx 4 MHz
+ */
+static inline unsigned get_usb_high_speed_rate(unsigned rate)
+{
+ return ((rate << 10) + 62) / 125;
+}
+
+void usb_stream_free(struct usb_stream_kernel *sk)
+{
+ struct usb_stream *s;
+ unsigned u;
+
+ for (u = 0; u < USB_STREAM_NURBS; ++u) {
+ usb_free_urb(sk->inurb[u]);
+ sk->inurb[u] = NULL;
+ usb_free_urb(sk->outurb[u]);
+ sk->outurb[u] = NULL;
+ }
+
+ s = sk->s;
+ if (!s)
+ return;
+
+ free_pages((unsigned long)sk->write_page, get_order(s->write_size));
+ sk->write_page = NULL;
+ free_pages((unsigned long)s, get_order(s->read_size));
+ sk->s = NULL;
+}
+
+struct usb_stream *usb_stream_new(struct usb_stream_kernel *sk,
+ struct usb_device *dev,
+ unsigned in_endpoint, unsigned out_endpoint,
+ unsigned sample_rate, unsigned use_packsize,
+ unsigned period_frames, unsigned frame_size)
+{
+ int packets, max_packsize;
+ int in_pipe, out_pipe;
+ int read_size = sizeof(struct usb_stream);
+ int write_size;
+ int usb_frames = dev->speed == USB_SPEED_HIGH ? 8000 : 1000;
+ int pg;
+
+ in_pipe = usb_rcvisocpipe(dev, in_endpoint);
+ out_pipe = usb_sndisocpipe(dev, out_endpoint);
+
+ max_packsize = use_packsize ?
+ use_packsize : usb_maxpacket(dev, in_pipe, 0);
+
+ /*
+ t_period = period_frames / sample_rate
+ iso_packs = t_period / t_iso_frame
+ = (period_frames / sample_rate) * (1 / t_iso_frame)
+ */
+
+ packets = period_frames * usb_frames / sample_rate + 1;
+
+ if (dev->speed == USB_SPEED_HIGH)
+ packets = (packets + 7) & ~7;
+
+ read_size += packets * USB_STREAM_URBDEPTH *
+ (max_packsize + sizeof(struct usb_stream_packet));
+
+ max_packsize = usb_maxpacket(dev, out_pipe, 1);
+ write_size = max_packsize * packets * USB_STREAM_URBDEPTH;
+
+ if (read_size >= 256*PAGE_SIZE || write_size >= 256*PAGE_SIZE) {
+ snd_printk(KERN_WARNING "a size exceeds 128*PAGE_SIZE\n");
+ goto out;
+ }
+
+ pg = get_order(read_size);
+ sk->s = (void *) __get_free_pages(GFP_KERNEL|__GFP_COMP|__GFP_ZERO, pg);
+ if (!sk->s) {
+ snd_printk(KERN_WARNING "couldn't __get_free_pages()\n");
+ goto out;
+ }
+ sk->s->cfg.version = USB_STREAM_INTERFACE_VERSION;
+
+ sk->s->read_size = read_size;
+
+ sk->s->cfg.sample_rate = sample_rate;
+ sk->s->cfg.frame_size = frame_size;
+ sk->n_o_ps = packets;
+ sk->s->inpackets = packets * USB_STREAM_URBDEPTH;
+ sk->s->cfg.period_frames = period_frames;
+ sk->s->period_size = frame_size * period_frames;
+
+ sk->s->write_size = write_size;
+ pg = get_order(write_size);
+
+ sk->write_page =
+ (void *)__get_free_pages(GFP_KERNEL|__GFP_COMP|__GFP_ZERO, pg);
+ if (!sk->write_page) {
+ snd_printk(KERN_WARNING "couldn't __get_free_pages()\n");
+ usb_stream_free(sk);
+ return NULL;
+ }
+
+ /* calculate the frequency in 16.16 format */
+ if (dev->speed == USB_SPEED_FULL)
+ sk->freqn = get_usb_full_speed_rate(sample_rate);
+ else
+ sk->freqn = get_usb_high_speed_rate(sample_rate);
+
+ init_urbs(sk, use_packsize, dev, in_pipe, out_pipe);
+ sk->s->state = usb_stream_stopped;
+out:
+ return sk->s;
+}
+
+
+/* start */
+
+static bool balance_check(struct usb_stream_kernel *sk, struct urb *urb)
+{
+ bool r;
+ if (unlikely(urb->status)) {
+ if (urb->status != -ESHUTDOWN && urb->status != -ENOENT)
+ snd_printk(KERN_WARNING "status=%i\n", urb->status);
+ sk->iso_frame_balance = 0x7FFFFFFF;
+ return false;
+ }
+ r = sk->iso_frame_balance == 0;
+ if (!r)
+ sk->i_urb = urb;
+ return r;
+}
+
+static bool balance_playback(struct usb_stream_kernel *sk, struct urb *urb)
+{
+ sk->iso_frame_balance += urb->number_of_packets;
+ return balance_check(sk, urb);
+}
+
+static bool balance_capture(struct usb_stream_kernel *sk, struct urb *urb)
+{
+ sk->iso_frame_balance -= urb->number_of_packets;
+ return balance_check(sk, urb);
+}
+
+static void subs_set_complete(struct urb **urbs, void (*complete)(struct urb *))
+{
+ int u;
+
+ for (u = 0; u < USB_STREAM_NURBS; u++) {
+ struct urb *urb = urbs[u];
+ urb->complete = complete;
+ }
+}
+
+int usb_stream_prepare_playback(struct usb_stream_kernel *sk, struct urb *inurb)
+{
+ struct usb_stream *s = sk->s;
+ struct urb *io;
+ struct usb_iso_packet_descriptor *id, *od;
+ int p, l = 0;
+
+ io = sk->idle_outurb;
+ od = io->iso_frame_desc;
+ io->transfer_buffer_length = 0;
+
+ for (p = 0; s->sync_packet < 0; ++p, ++s->sync_packet) {
+ struct urb *ii = sk->completed_inurb;
+ id = ii->iso_frame_desc +
+ ii->number_of_packets + s->sync_packet;
+ l = id->actual_length;
+
+ od[p].length = l;
+ od[p].offset = io->transfer_buffer_length;
+ io->transfer_buffer_length += l;
+ }
+
+ for (;
+ s->sync_packet < inurb->number_of_packets && p < sk->n_o_ps;
+ ++p, ++s->sync_packet) {
+ l = inurb->iso_frame_desc[s->sync_packet].actual_length;
+
+ if (s->idle_outsize + io->transfer_buffer_length + l >
+ s->period_size)
+ goto check_ok;
+
+ od[p].length = l;
+ od[p].offset = io->transfer_buffer_length;
+ io->transfer_buffer_length += l;
+ }
+
+check_ok:
+ s->sync_packet -= inurb->number_of_packets;
+ if (s->sync_packet < -2 || s->sync_packet > 0) {
+ snd_printk(KERN_WARNING "invalid sync_packet = %i;"
+ " p=%i nop=%i %i %x %x %x > %x\n",
+ s->sync_packet, p, inurb->number_of_packets,
+ s->idle_outsize + io->transfer_buffer_length + l,
+ s->idle_outsize, io->transfer_buffer_length, l,
+ s->period_size);
+ return -1;
+ }
+ if (io->transfer_buffer_length % s->cfg.frame_size) {
+ snd_printk(KERN_WARNING"invalid outsize = %i\n",
+ io->transfer_buffer_length);
+ return -1;
+ }
+ s->idle_outsize += io->transfer_buffer_length - s->period_size;
+ io->number_of_packets = p;
+ if (s->idle_outsize > 0) {
+ snd_printk(KERN_WARNING "idle=%i\n", s->idle_outsize);
+ return -1;
+ }
+ return 0;
+}
+
+static void prepare_inurb(int number_of_packets, struct urb *iu)
+{
+ struct usb_iso_packet_descriptor *id;
+ int p;
+
+ iu->number_of_packets = number_of_packets;
+ id = iu->iso_frame_desc;
+ id->offset = 0;
+ for (p = 0; p < iu->number_of_packets - 1; ++p)
+ id[p + 1].offset = id[p].offset + id[p].length;
+
+ iu->transfer_buffer_length =
+ id[0].length * iu->number_of_packets;
+}
+
+static int submit_urbs(struct usb_stream_kernel *sk,
+ struct urb *inurb, struct urb *outurb)
+{
+ int err;
+ prepare_inurb(sk->idle_outurb->number_of_packets, sk->idle_inurb);
+ err = usb_submit_urb(sk->idle_inurb, GFP_ATOMIC);
+ if (err < 0) {
+ snd_printk(KERN_ERR "%i\n", err);
+ return err;
+ }
+ sk->idle_inurb = sk->completed_inurb;
+ sk->completed_inurb = inurb;
+ err = usb_submit_urb(sk->idle_outurb, GFP_ATOMIC);
+ if (err < 0) {
+ snd_printk(KERN_ERR "%i\n", err);
+ return err;
+ }
+ sk->idle_outurb = sk->completed_outurb;
+ sk->completed_outurb = outurb;
+ return 0;
+}
+
+#ifdef DEBUG_LOOP_BACK
+/*
+ This loop_back() shows how to read/write the period data.
+ */
+static void loop_back(struct usb_stream *s)
+{
+ char *i, *o;
+ int il, ol, l, p;
+ struct urb *iu;
+ struct usb_iso_packet_descriptor *id;
+
+ o = s->playback1st_to;
+ ol = s->playback1st_size;
+ l = 0;
+
+ if (s->insplit_pack >= 0) {
+ iu = sk->idle_inurb;
+ id = iu->iso_frame_desc;
+ p = s->insplit_pack;
+ } else
+ goto second;
+loop:
+ for (; p < iu->number_of_packets && l < s->period_size; ++p) {
+ i = iu->transfer_buffer + id[p].offset;
+ il = id[p].actual_length;
+ if (l + il > s->period_size)
+ il = s->period_size - l;
+ if (il <= ol) {
+ memcpy(o, i, il);
+ o += il;
+ ol -= il;
+ } else {
+ memcpy(o, i, ol);
+ singen_6pack(o, ol);
+ o = s->playback_to;
+ memcpy(o, i + ol, il - ol);
+ o += il - ol;
+ ol = s->period_size - s->playback1st_size;
+ }
+ l += il;
+ }
+ if (iu == sk->completed_inurb) {
+ if (l != s->period_size)
+ printk(KERN_DEBUG"%s:%i %i\n", __func__, __LINE__,
+ l/(int)s->cfg.frame_size);
+
+ return;
+ }
+second:
+ iu = sk->completed_inurb;
+ id = iu->iso_frame_desc;
+ p = 0;
+ goto loop;
+
+}
+#else
+static void loop_back(struct usb_stream *s)
+{
+}
+#endif
+
+static void stream_idle(struct usb_stream_kernel *sk,
+ struct urb *inurb, struct urb *outurb)
+{
+ struct usb_stream *s = sk->s;
+ int l, p;
+ int insize = s->idle_insize;
+ int urb_size = 0;
+
+ s->inpacket_split = s->next_inpacket_split;
+ s->inpacket_split_at = s->next_inpacket_split_at;
+ s->next_inpacket_split = -1;
+ s->next_inpacket_split_at = 0;
+
+ for (p = 0; p < inurb->number_of_packets; ++p) {
+ struct usb_iso_packet_descriptor *id = inurb->iso_frame_desc;
+ l = id[p].actual_length;
+ if (unlikely(l == 0 || id[p].status)) {
+ snd_printk(KERN_WARNING "underrun, status=%u\n",
+ id[p].status);
+ goto err_out;
+ }
+ s->inpacket_head++;
+ s->inpacket_head %= s->inpackets;
+ if (s->inpacket_split == -1)
+ s->inpacket_split = s->inpacket_head;
+
+ s->inpacket[s->inpacket_head].offset =
+ id[p].offset + (inurb->transfer_buffer - (void *)s);
+ s->inpacket[s->inpacket_head].length = l;
+ if (insize + l > s->period_size &&
+ s->next_inpacket_split == -1) {
+ s->next_inpacket_split = s->inpacket_head;
+ s->next_inpacket_split_at = s->period_size - insize;
+ }
+ insize += l;
+ urb_size += l;
+ }
+ s->idle_insize += urb_size - s->period_size;
+ if (s->idle_insize < 0) {
+ snd_printk(KERN_WARNING "%i\n",
+ (s->idle_insize)/(int)s->cfg.frame_size);
+ goto err_out;
+ }
+ s->insize_done += urb_size;
+
+ l = s->idle_outsize;
+ s->outpacket[0].offset = (sk->idle_outurb->transfer_buffer -
+ sk->write_page) - l;
+
+ if (usb_stream_prepare_playback(sk, inurb) < 0)
+ goto err_out;
+
+ s->outpacket[0].length = sk->idle_outurb->transfer_buffer_length + l;
+ s->outpacket[1].offset = sk->completed_outurb->transfer_buffer -
+ sk->write_page;
+
+ if (submit_urbs(sk, inurb, outurb) < 0)
+ goto err_out;
+
+ loop_back(s);
+ s->periods_done++;
+ wake_up_all(&sk->sleep);
+ return;
+err_out:
+ s->state = usb_stream_xrun;
+ wake_up_all(&sk->sleep);
+}
+
+static void i_capture_idle(struct urb *urb)
+{
+ struct usb_stream_kernel *sk = urb->context;
+ if (balance_capture(sk, urb))
+ stream_idle(sk, urb, sk->i_urb);
+}
+
+static void i_playback_idle(struct urb *urb)
+{
+ struct usb_stream_kernel *sk = urb->context;
+ if (balance_playback(sk, urb))
+ stream_idle(sk, sk->i_urb, urb);
+}
+
+static void stream_start(struct usb_stream_kernel *sk,
+ struct urb *inurb, struct urb *outurb)
+{
+ struct usb_stream *s = sk->s;
+ if (s->state >= usb_stream_sync1) {
+ int l, p, max_diff, max_diff_0;
+ int urb_size = 0;
+ unsigned frames_per_packet, min_frames = 0;
+ frames_per_packet = (s->period_size - s->idle_insize);
+ frames_per_packet <<= 8;
+ frames_per_packet /=
+ s->cfg.frame_size * inurb->number_of_packets;
+ frames_per_packet++;
+
+ max_diff_0 = s->cfg.frame_size;
+ if (s->cfg.period_frames >= 256)
+ max_diff_0 <<= 1;
+ if (s->cfg.period_frames >= 1024)
+ max_diff_0 <<= 1;
+ max_diff = max_diff_0;
+ for (p = 0; p < inurb->number_of_packets; ++p) {
+ int diff;
+ l = inurb->iso_frame_desc[p].actual_length;
+ urb_size += l;
+
+ min_frames += frames_per_packet;
+ diff = urb_size -
+ (min_frames >> 8) * s->cfg.frame_size;
+ if (diff < max_diff) {
+ snd_printdd(KERN_DEBUG "%i %i %i %i\n",
+ s->insize_done,
+ urb_size / (int)s->cfg.frame_size,
+ inurb->number_of_packets, diff);
+ max_diff = diff;
+ }
+ }
+ s->idle_insize -= max_diff - max_diff_0;
+ s->idle_insize += urb_size - s->period_size;
+ if (s->idle_insize < 0) {
+ snd_printk("%i %i %i\n",
+ s->idle_insize, urb_size, s->period_size);
+ return;
+ } else if (s->idle_insize == 0) {
+ s->next_inpacket_split =
+ (s->inpacket_head + 1) % s->inpackets;
+ s->next_inpacket_split_at = 0;
+ } else {
+ unsigned split = s->inpacket_head;
+ l = s->idle_insize;
+ while (l > s->inpacket[split].length) {
+ l -= s->inpacket[split].length;
+ if (split == 0)
+ split = s->inpackets - 1;
+ else
+ split--;
+ }
+ s->next_inpacket_split = split;
+ s->next_inpacket_split_at =
+ s->inpacket[split].length - l;
+ }
+
+ s->insize_done += urb_size;
+
+ if (usb_stream_prepare_playback(sk, inurb) < 0)
+ return;
+
+ } else
+ playback_prep_freqn(sk, sk->idle_outurb);
+
+ if (submit_urbs(sk, inurb, outurb) < 0)
+ return;
+
+ if (s->state == usb_stream_sync1 && s->insize_done > 360000) {
+ /* just guesswork ^^^^^^ */
+ s->state = usb_stream_ready;
+ subs_set_complete(sk->inurb, i_capture_idle);
+ subs_set_complete(sk->outurb, i_playback_idle);
+ }
+}
+
+static void i_capture_start(struct urb *urb)
+{
+ struct usb_iso_packet_descriptor *id = urb->iso_frame_desc;
+ struct usb_stream_kernel *sk = urb->context;
+ struct usb_stream *s = sk->s;
+ int p;
+ int empty = 0;
+
+ if (urb->status) {
+ snd_printk(KERN_WARNING "status=%i\n", urb->status);
+ return;
+ }
+
+ for (p = 0; p < urb->number_of_packets; ++p) {
+ int l = id[p].actual_length;
+ if (l < s->cfg.frame_size) {
+ ++empty;
+ if (s->state >= usb_stream_sync0) {
+ snd_printk(KERN_WARNING "%i\n", l);
+ return;
+ }
+ }
+ s->inpacket_head++;
+ s->inpacket_head %= s->inpackets;
+ s->inpacket[s->inpacket_head].offset =
+ id[p].offset + (urb->transfer_buffer - (void *)s);
+ s->inpacket[s->inpacket_head].length = l;
+ }
+#ifdef SHOW_EMPTY
+ if (empty) {
+ printk(KERN_DEBUG"%s:%i: %i", __func__, __LINE__,
+ urb->iso_frame_desc[0].actual_length);
+ for (pack = 1; pack < urb->number_of_packets; ++pack) {
+ int l = urb->iso_frame_desc[pack].actual_length;
+ printk(" %i", l);
+ }
+ printk("\n");
+ }
+#endif
+ if (!empty && s->state < usb_stream_sync1)
+ ++s->state;
+
+ if (balance_capture(sk, urb))
+ stream_start(sk, urb, sk->i_urb);
+}
+
+static void i_playback_start(struct urb *urb)
+{
+ struct usb_stream_kernel *sk = urb->context;
+ if (balance_playback(sk, urb))
+ stream_start(sk, sk->i_urb, urb);
+}
+
+int usb_stream_start(struct usb_stream_kernel *sk)
+{
+ struct usb_stream *s = sk->s;
+ int frame = 0, iters = 0;
+ int u, err;
+ int try = 0;
+
+ if (s->state != usb_stream_stopped)
+ return -EAGAIN;
+
+ subs_set_complete(sk->inurb, i_capture_start);
+ subs_set_complete(sk->outurb, i_playback_start);
+ memset(sk->write_page, 0, s->write_size);
+dotry:
+ s->insize_done = 0;
+ s->idle_insize = 0;
+ s->idle_outsize = 0;
+ s->sync_packet = -1;
+ s->inpacket_head = -1;
+ sk->iso_frame_balance = 0;
+ ++try;
+ for (u = 0; u < 2; u++) {
+ struct urb *inurb = sk->inurb[u];
+ struct urb *outurb = sk->outurb[u];
+ playback_prep_freqn(sk, outurb);
+ inurb->number_of_packets = outurb->number_of_packets;
+ inurb->transfer_buffer_length =
+ inurb->number_of_packets *
+ inurb->iso_frame_desc[0].length;
+ preempt_disable();
+ if (u == 0) {
+ int now;
+ struct usb_device *dev = inurb->dev;
+ frame = usb_get_current_frame_number(dev);
+ do {
+ now = usb_get_current_frame_number(dev);
+ ++iters;
+ } while (now > -1 && now == frame);
+ }
+ err = usb_submit_urb(inurb, GFP_ATOMIC);
+ if (err < 0) {
+ preempt_enable();
+ snd_printk(KERN_ERR"usb_submit_urb(sk->inurb[%i])"
+ " returned %i\n", u, err);
+ return err;
+ }
+ err = usb_submit_urb(outurb, GFP_ATOMIC);
+ if (err < 0) {
+ preempt_enable();
+ snd_printk(KERN_ERR"usb_submit_urb(sk->outurb[%i])"
+ " returned %i\n", u, err);
+ return err;
+ }
+ preempt_enable();
+ if (inurb->start_frame != outurb->start_frame) {
+ snd_printd(KERN_DEBUG
+ "u[%i] start_frames differ in:%u out:%u\n",
+ u, inurb->start_frame, outurb->start_frame);
+ goto check_retry;
+ }
+ }
+ snd_printdd(KERN_DEBUG "%i %i\n", frame, iters);
+ try = 0;
+check_retry:
+ if (try) {
+ usb_stream_stop(sk);
+ if (try < 5) {
+ msleep(1500);
+ snd_printd(KERN_DEBUG "goto dotry;\n");
+ goto dotry;
+ }
+ snd_printk(KERN_WARNING"couldn't start"
+ " all urbs on the same start_frame.\n");
+ return -EFAULT;
+ }
+
+ sk->idle_inurb = sk->inurb[USB_STREAM_NURBS - 2];
+ sk->idle_outurb = sk->outurb[USB_STREAM_NURBS - 2];
+ sk->completed_inurb = sk->inurb[USB_STREAM_NURBS - 1];
+ sk->completed_outurb = sk->outurb[USB_STREAM_NURBS - 1];
+
+/* wait, check */
+ {
+ int wait_ms = 3000;
+ while (s->state != usb_stream_ready && wait_ms > 0) {
+ snd_printdd(KERN_DEBUG "%i\n", s->state);
+ msleep(200);
+ wait_ms -= 200;
+ }
+ }
+
+ return s->state == usb_stream_ready ? 0 : -EFAULT;
+}
+
+
+/* stop */
+
+void usb_stream_stop(struct usb_stream_kernel *sk)
+{
+ int u;
+ if (!sk->s)
+ return;
+ for (u = 0; u < USB_STREAM_NURBS; ++u) {
+ usb_kill_urb(sk->inurb[u]);
+ usb_kill_urb(sk->outurb[u]);
+ }
+ sk->s->state = usb_stream_stopped;
+ msleep(400);
+}