diff options
| author | Calvin Owens <jcalvinowens@gmail.com> | 2013-04-12 22:33:59 -0500 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-05-13 15:02:17 +0100 |
| commit | 40de8047654debace75db0f04aebbbaace5bdd26 (patch) | |
| tree | 41fc40f3d4395812bfca5aca490ecc5e1228a991 /sound | |
| parent | 1b136c71e8858b068b7813fed270eb4668a217ca (diff) | |
ALSA: usb: Add quirk for 192KHz recording on E-Mu devices
commit 1539d4f82ad534431cc67935e8e442ccf107d17d upstream.
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>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[bwh: Backported to 3.2: adjust filenames, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/usb/card.h | 1 | ||||
| -rw-r--r-- | sound/usb/endpoint.c | 3 | ||||
| -rw-r--r-- | sound/usb/quirks.c | 1 |
3 files changed, 4 insertions, 1 deletions
diff --git a/sound/usb/card.h b/sound/usb/card.h index 665e29734ab..2b7559c7586 100644 --- a/sound/usb/card.h +++ b/sound/usb/card.h @@ -73,6 +73,7 @@ struct snd_usb_substream { unsigned int fill_max: 1; /* fill max packet size always */ 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/endpoint.c b/sound/usb/endpoint.c index 9ab2b3e2222..5ebe8c4403e 100644 --- a/sound/usb/endpoint.c +++ b/sound/usb/endpoint.c @@ -458,7 +458,7 @@ static int 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("frame %d active: %d\n", i, urb->iso_frame_desc[i].status); // continue; @@ -898,6 +898,7 @@ void snd_usb_init_substream(struct snd_usb_stream *as, subs->speed = snd_usb_get_speed(subs->dev); if (subs->speed >= USB_SPEED_HIGH) subs->ops.prepare_sync = prepare_capture_sync_urb_hs; + subs->pkt_offset_adj = 0; snd_usb_set_pcm_ops(as->pcm, stream); diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c index dfbd65d4837..42eeee8da15 100644 --- a/sound/usb/quirks.c +++ b/sound/usb/quirks.c @@ -744,6 +744,7 @@ 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, |