From: Calvin Owens Date: Sat, 13 Apr 2013 03:33:59 +0000 (-0500) Subject: ALSA: usb: Add quirk for 192KHz recording on E-Mu devices X-Git-Tag: v3.2.45~91 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=40de8047654debace75db0f04aebbbaace5bdd26;p=thirdparty%2Fkernel%2Fstable.git 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 Signed-off-by: Takashi Iwai [bwh: Backported to 3.2: adjust filenames, context] Signed-off-by: Ben Hutchings --- diff --git a/sound/usb/card.h b/sound/usb/card.h index 665e29734ab9a..2b7559c7586ab 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 9ab2b3e222247..5ebe8c4403e0a 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 dfbd65d483705..42eeee8da158b 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,