diff options
| author | Calvin Owens <jcalvinowens@gmail.com> | 2013-04-12 22:33:59 -0500 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2013-04-13 10:58:03 +0200 |
| commit | 1539d4f82ad534431cc67935e8e442ccf107d17d (patch) | |
| tree | edb34bea8a89d757f14bbf099329285c036f7279 /sound/usb | |
| parent | b26b51166848758d740ab638fc27789228a51c97 (diff) | |
| download | linux-1539d4f82ad534431cc67935e8e442ccf107d17d.tar.gz | |
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.h | 1 | ||||
| -rw-r--r-- | sound/usb/pcm.c | 2 | ||||
| -rw-r--r-- | sound/usb/quirks.c | 1 | ||||
| -rw-r--r-- | sound/usb/stream.c | 1 |
4 files changed, 4 insertions, 1 deletions
diff --git a/sound/usb/card.h b/sound/usb/card.h index 8a751b4887ea..d32ea411545a 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 815a37d2e3e0..9916c85d8cdb 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 292798185afc..175fbb7d334a 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 74beea237801..8951f77a7201 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); |