From 1539d4f82ad534431cc67935e8e442ccf107d17d Mon Sep 17 00:00:00 2001 From: Calvin Owens Date: Fri, 12 Apr 2013 22:33:59 -0500 Subject: 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 Cc: Signed-off-by: Takashi Iwai --- sound/usb/quirks.c | 1 + 1 file changed, 1 insertion(+) (limited to 'sound/usb/quirks.c') 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, -- cgit v1.2.3