aboutsummaryrefslogtreecommitdiff
path: root/sound/usb/urb.c
diff options
context:
space:
mode:
Diffstat (limited to 'sound/usb/urb.c')
-rw-r--r--sound/usb/urb.c170
1 files changed, 58 insertions, 112 deletions
diff --git a/sound/usb/urb.c b/sound/usb/urb.c
index 8deeaad10f1..e184349aee8 100644
--- a/sound/usb/urb.c
+++ b/sound/usb/urb.c
@@ -225,6 +225,7 @@ int snd_usb_init_substream_urbs(struct snd_usb_substream *subs,
else
subs->freqn = get_usb_high_speed_rate(rate);
subs->freqm = subs->freqn;
+ subs->freqshift = INT_MIN;
/* calculate max. frequency */
if (subs->maxpacksize) {
/* whatever fits into a max. size packet */
@@ -513,11 +514,10 @@ static int retire_paused_capture_urb(struct snd_usb_substream *subs,
/*
- * prepare urb for full speed playback sync pipe
+ * prepare urb for playback sync pipe
*
* set up the offset and length to receive the current frequency.
*/
-
static int prepare_playback_sync_urb(struct snd_usb_substream *subs,
struct snd_pcm_runtime *runtime,
struct urb *urb)
@@ -525,103 +525,78 @@ static int prepare_playback_sync_urb(struct snd_usb_substream *subs,
struct snd_urb_ctx *ctx = urb->context;
urb->dev = ctx->subs->dev; /* we need to set this at each time */
- urb->iso_frame_desc[0].length = 3;
+ urb->iso_frame_desc[0].length = min(4u, ctx->subs->syncmaxsize);
urb->iso_frame_desc[0].offset = 0;
return 0;
}
/*
- * prepare urb for high speed playback sync pipe
+ * process after playback sync complete
*
- * set up the offset and length to receive the current frequency.
- */
-
-static int prepare_playback_sync_urb_hs(struct snd_usb_substream *subs,
- struct snd_pcm_runtime *runtime,
- struct urb *urb)
-{
- struct snd_urb_ctx *ctx = urb->context;
-
- urb->dev = ctx->subs->dev; /* we need to set this at each time */
- urb->iso_frame_desc[0].length = 4;
- urb->iso_frame_desc[0].offset = 0;
- return 0;
-}
-
-/*
- * process after full speed playback sync complete
- *
- * retrieve the current 10.14 frequency from pipe, and set it.
- * the value is referred in prepare_playback_urb().
+ * Full speed devices report feedback values in 10.14 format as samples per
+ * frame, high speed devices in 16.16 format as samples per microframe.
+ * Because the Audio Class 1 spec was written before USB 2.0, many high speed
+ * devices use a wrong interpretation, some others use an entirely different
+ * format. Therefore, we cannot predict what format any particular device uses
+ * and must detect it automatically.
*/
static int retire_playback_sync_urb(struct snd_usb_substream *subs,
struct snd_pcm_runtime *runtime,
struct urb *urb)
{
unsigned int f;
+ int shift;
unsigned long flags;
- if (urb->iso_frame_desc[0].status == 0 &&
- urb->iso_frame_desc[0].actual_length == 3) {
- f = combine_triple((u8*)urb->transfer_buffer) << 2;
- if (f >= subs->freqn - subs->freqn / 8 && f <= subs->freqmax) {
- spin_lock_irqsave(&subs->lock, flags);
- subs->freqm = f;
- spin_unlock_irqrestore(&subs->lock, flags);
- }
- }
-
- return 0;
-}
+ if (urb->iso_frame_desc[0].status != 0 ||
+ urb->iso_frame_desc[0].actual_length < 3)
+ return 0;
-/*
- * process after high speed playback sync complete
- *
- * retrieve the current 12.13 frequency from pipe, and set it.
- * the value is referred in prepare_playback_urb().
- */
-static int retire_playback_sync_urb_hs(struct snd_usb_substream *subs,
- struct snd_pcm_runtime *runtime,
- struct urb *urb)
-{
- unsigned int f;
- unsigned long flags;
+ f = le32_to_cpup(urb->transfer_buffer);
+ if (urb->iso_frame_desc[0].actual_length == 3)
+ f &= 0x00ffffff;
+ else
+ f &= 0x0fffffff;
+ if (f == 0)
+ return 0;
- if (urb->iso_frame_desc[0].status == 0 &&
- urb->iso_frame_desc[0].actual_length == 4) {
- f = combine_quad((u8*)urb->transfer_buffer) & 0x0fffffff;
- if (f >= subs->freqn - subs->freqn / 8 && f <= subs->freqmax) {
- spin_lock_irqsave(&subs->lock, flags);
- subs->freqm = f;
- spin_unlock_irqrestore(&subs->lock, flags);
+ if (unlikely(subs->freqshift == INT_MIN)) {
+ /*
+ * The first time we see a feedback value, determine its format
+ * by shifting it left or right until it matches the nominal
+ * frequency value. This assumes that the feedback does not
+ * differ from the nominal value more than +50% or -25%.
+ */
+ shift = 0;
+ while (f < subs->freqn - subs->freqn / 4) {
+ f <<= 1;
+ shift++;
+ }
+ while (f > subs->freqn + subs->freqn / 2) {
+ f >>= 1;
+ shift--;
}
+ subs->freqshift = shift;
}
+ else if (subs->freqshift >= 0)
+ f <<= subs->freqshift;
+ else
+ f >>= -subs->freqshift;
- return 0;
-}
-
-/*
- * process after E-Mu 0202/0404/Tracker Pre high speed playback sync complete
- *
- * These devices return the number of samples per packet instead of the number
- * of samples per microframe.
- */
-static int retire_playback_sync_urb_hs_emu(struct snd_usb_substream *subs,
- struct snd_pcm_runtime *runtime,
- struct urb *urb)
-{
- unsigned int f;
- unsigned long flags;
-
- if (urb->iso_frame_desc[0].status == 0 &&
- urb->iso_frame_desc[0].actual_length == 4) {
- f = combine_quad((u8*)urb->transfer_buffer) & 0x0fffffff;
- f >>= subs->datainterval;
- if (f >= subs->freqn - subs->freqn / 8 && f <= subs->freqmax) {
- spin_lock_irqsave(&subs->lock, flags);
- subs->freqm = f;
- spin_unlock_irqrestore(&subs->lock, flags);
- }
+ if (likely(f >= subs->freqn - subs->freqn / 8 && f <= subs->freqmax)) {
+ /*
+ * If the frequency looks valid, set it.
+ * This value is referred to in prepare_playback_urb().
+ */
+ spin_lock_irqsave(&subs->lock, flags);
+ subs->freqm = f;
+ spin_unlock_irqrestore(&subs->lock, flags);
+ } else {
+ /*
+ * Out of range; maybe the shift value is wrong.
+ * Reset it so that we autodetect again the next time.
+ */
+ subs->freqshift = INT_MIN;
}
return 0;
@@ -878,21 +853,6 @@ static struct snd_urb_ops audio_urb_ops[2] = {
},
};
-static struct snd_urb_ops audio_urb_ops_high_speed[2] = {
- {
- .prepare = prepare_nodata_playback_urb,
- .retire = retire_playback_urb,
- .prepare_sync = prepare_playback_sync_urb_hs,
- .retire_sync = retire_playback_sync_urb_hs,
- },
- {
- .prepare = prepare_capture_urb,
- .retire = retire_capture_urb,
- .prepare_sync = prepare_capture_sync_urb_hs,
- .retire_sync = retire_capture_sync_urb,
- },
-};
-
/*
* initialize the substream instance.
*/
@@ -909,23 +869,9 @@ void snd_usb_init_substream(struct snd_usb_stream *as,
subs->direction = stream;
subs->dev = as->chip->dev;
subs->txfr_quirk = as->chip->txfr_quirk;
- if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL) {
- subs->ops = audio_urb_ops[stream];
- } else {
- subs->ops = audio_urb_ops_high_speed[stream];
- switch (as->chip->usb_id) {
- case USB_ID(0x041e, 0x3f02): /* E-Mu 0202 USB */
- case USB_ID(0x041e, 0x3f04): /* E-Mu 0404 USB */
- case USB_ID(0x041e, 0x3f0a): /* E-Mu Tracker Pre */
- subs->ops.retire_sync = retire_playback_sync_urb_hs_emu;
- break;
- case USB_ID(0x0763, 0x2080): /* M-Audio Fast Track Ultra 8 */
- case USB_ID(0x0763, 0x2081): /* M-Audio Fast Track Ultra 8R */
- subs->ops.prepare_sync = prepare_playback_sync_urb;
- subs->ops.retire_sync = retire_playback_sync_urb;
- break;
- }
- }
+ subs->ops = audio_urb_ops[stream];
+ if (snd_usb_get_speed(subs->dev) >= USB_SPEED_HIGH)
+ subs->ops.prepare_sync = prepare_capture_sync_urb_hs;
snd_usb_set_pcm_ops(as->pcm, stream);
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-20 18:09:38 +0000