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authorClemens Ladisch <clemens@ladisch.de>2008-02-25 11:01:00 +0100
committerTakashi Iwai <tiwai@suse.de>2008-02-29 11:28:15 +0100
commitd513202efd5bb9974545ef1c7f951467b21eb3a5 (patch)
tree56dd0f3aa631713717b6e0415d410be99432e7c9 /sound
parentee47fd12d73706edb2a10efd05d5eed15b4d1e08 (diff)
downloadlinux-2.6.34-ux500-d513202efd5bb9974545ef1c7f951467b21eb3a5.tar.gz
[ALSA] usb-audio: add workaround for broken E-Mu frequency feedback
Add a workaround for the feedback pipe of E-Mu 0202/0404 USB devices that reports the number of samples per packet instead of the number of samples per microframe. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
-rw-r--r--sound/usb/usbaudio.c38
1 files changed, 36 insertions, 2 deletions
diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index 8fa93566570..675672f313b 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -479,6 +479,33 @@ static int retire_playback_sync_urb_hs(struct snd_usb_substream *subs,
return 0;
}
+/*
+ * process after E-Mu 0202/0404 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);
+ }
+ }
+
+ return 0;
+}
+
/* determine the number of frames in the next packet */
static int snd_usb_audio_next_packet_size(struct snd_usb_substream *subs)
{
@@ -2219,10 +2246,17 @@ static void init_substream(struct snd_usb_stream *as, int stream, struct audiofo
subs->stream = as;
subs->direction = stream;
subs->dev = as->chip->dev;
- if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL)
+ if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL) {
subs->ops = audio_urb_ops[stream];
- else
+ } 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 */
+ subs->ops.retire_sync = retire_playback_sync_urb_hs_emu;
+ break;
+ }
+ }
snd_pcm_set_ops(as->pcm, stream,
stream == SNDRV_PCM_STREAM_PLAYBACK ?
&snd_usb_playback_ops : &snd_usb_capture_ops);