| From: Calvin Owens <jcalvinowens@gmail.com> |
| Date: Fri, 12 Apr 2013 22:33:59 -0500 |
| Subject: 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> |
| --- |
| --- 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 */ |
| |
| --- a/sound/usb/endpoint.c |
| +++ b/sound/usb/endpoint.c |
| @@ -458,7 +458,7 @@ static int retire_capture_urb(struct snd |
| 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_u |
| 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); |
| |
| --- a/sound/usb/quirks.c |
| +++ b/sound/usb/quirks.c |
| @@ -744,6 +744,7 @@ static void set_format_emu_quirk(struct |
| 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, |