Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / sound / usb / usx2y / usb_stream.c
diff --git a/kernel/sound/usb/usx2y/usb_stream.c b/kernel/sound/usb/usx2y/usb_stream.c
new file mode 100644 (file)
index 0000000..bf618e1
--- /dev/null
@@ -0,0 +1,753 @@
+/*
+ * 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 <linux/gfp.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;
+       int pack, lb = 0;
+
+       for (pack = 0; pack < sk->n_o_ps; pack++) {
+               int l = usb_stream_next_packet_size(sk);
+               if (s->idle_outsize + lb + l > s->period_size)
+                       goto check;
+
+               sk->out_phase = sk->out_phase_peeked;
+               urb->iso_frame_desc[pack].offset = lb;
+               urb->iso_frame_desc[pack].length = l;
+               lb += l;
+       }
+       snd_printdd(KERN_DEBUG "%i\n", lb);
+
+check:
+       urb->number_of_packets = pack;
+       urb->transfer_buffer_length = lb;
+       s->idle_outsize += lb - s->period_size;
+       snd_printdd(KERN_DEBUG "idle=%i ul=%i ps=%i\n", s->idle_outsize,
+                   lb, 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_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;
+       }
+}
+
+static 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 = 0, lb = 0, l = 0;
+
+       io = sk->idle_outurb;
+       od = io->iso_frame_desc;
+
+       for (; 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 = lb;
+               lb += 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 + lb + l > s->period_size)
+                       goto check_ok;
+
+               od[p].length = l;
+               od[p].offset = lb;
+               lb += l;
+       }
+
+check_ok:
+       s->sync_packet -= inurb->number_of_packets;
+       if (unlikely(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 + lb + l,
+                          s->idle_outsize, lb,  l,
+                          s->period_size);
+               return -1;
+       }
+       if (unlikely(lb % s->cfg.frame_size)) {
+               snd_printk(KERN_WARNING"invalid outsize = %i\n",
+                          lb);
+               return -1;
+       }
+       s->idle_outsize += lb - s->period_size;
+       io->number_of_packets = p;
+       io->transfer_buffer_length = lb;
+       if (s->idle_outsize <= 0)
+               return 0;
+
+       snd_printk(KERN_WARNING "idle=%i\n", s->idle_outsize);
+       return -1;
+}
+
+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(KERN_WARNING "%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;
+
+               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) {
+                       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) {
+                       snd_printk(KERN_ERR"usb_submit_urb(sk->outurb[%i])"
+                                  " returned %i\n", u, err);
+                       return err;
+               }
+
+               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);
+}