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authorCalvin Owens <jcalvinowens@gmail.com>2013-04-12 22:33:59 -0500
committerTakashi Iwai <tiwai@suse.de>2013-04-13 10:58:03 +0200
commit1539d4f82ad534431cc67935e8e442ccf107d17d (patch)
treeedb34bea8a89d757f14bbf099329285c036f7279 /sound/usb
parentb26b51166848758d740ab638fc27789228a51c97 (diff)
ALSA: usb: Add quirk for 192KHz recording on E-Mu devices
When recording at 176.2KHz or 192Khz, the device adds a 32-bit length header to the capture packets, which obviously needs to be ignored for recording to work properly. Userspace expected: L0 L1 L2 R0 R1 R2 ...but actually got: R2 L0 L1 L2 R0 R1 Also, the last byte of the length header being interpreted as L0 of the first sample caused spikes every 0.5ms, resulting in a loud 16KHz tone (about the highest 'B' on a piano) being present throughout captures. Tested at all sample rates on an E-Mu 0404USB, and tested for regressions on a generic USB headset. Signed-off-by: Calvin Owens <jcalvinowens@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb')
-rw-r--r--sound/usb/card.h1
-rw-r--r--sound/usb/pcm.c2
-rw-r--r--sound/usb/quirks.c1
-rw-r--r--sound/usb/stream.c1
4 files changed, 4 insertions, 1 deletions
diff --git a/sound/usb/card.h b/sound/usb/card.h
index 8a751b4887e..d32ea411545 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -116,6 +116,7 @@ struct snd_usb_substream {
unsigned int altset_idx; /* USB data format: index of alternate setting */
unsigned int txfr_quirk:1; /* allow sub-frame alignment */
unsigned int fmt_type; /* USB audio format type (1-3) */
+ unsigned int pkt_offset_adj; /* Bytes to drop from beginning of packets (for non-compliant devices) */
unsigned int running: 1; /* running status */
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 815a37d2e3e..9916c85d8cd 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -1162,7 +1162,7 @@ static void retire_capture_urb(struct snd_usb_substream *subs,
stride = runtime->frame_bits >> 3;
for (i = 0; i < urb->number_of_packets; i++) {
- cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
+ cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset + subs->pkt_offset_adj;
if (urb->iso_frame_desc[i].status && printk_ratelimit()) {
snd_printdd(KERN_ERR "frame %d active: %d\n", i, urb->iso_frame_desc[i].status);
// continue;
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 292798185af..175fbb7d334 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -854,6 +854,7 @@ static void set_format_emu_quirk(struct snd_usb_substream *subs,
break;
}
snd_emuusb_set_samplerate(subs->stream->chip, emu_samplerate_id);
+ subs->pkt_offset_adj = (emu_samplerate_id >= EMU_QUIRK_SR_176400HZ) ? 4 : 0;
}
void snd_usb_set_format_quirk(struct snd_usb_substream *subs,
diff --git a/sound/usb/stream.c b/sound/usb/stream.c
index 74beea23780..8951f77a720 100644
--- a/sound/usb/stream.c
+++ b/sound/usb/stream.c
@@ -93,6 +93,7 @@ static void snd_usb_init_substream(struct snd_usb_stream *as,
subs->dev = as->chip->dev;
subs->txfr_quirk = as->chip->txfr_quirk;
subs->speed = snd_usb_get_speed(subs->dev);
+ subs->pkt_offset_adj = 0;
snd_usb_set_pcm_ops(as->pcm, stream);