@@ -110,6 +110,7 @@ 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 */
@@ -1014,7 +1014,7 @@ 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;
@@ -748,6 +748,7 @@ 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,
@@ -91,6 +91,7 @@ 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);
This is a note to let you know that I have just added a patch titled ALSA: usb: Add quirk for 192KHz recording on E-Mu devices to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 701a3ffbe2f3511b6fee0d0b45f094be6322cd54 Mon Sep 17 00:00:00 2001 From: Calvin Owens <jcalvinowens@gmail.com> Date: Fri, 12 Apr 2013 22:33:59 -0500 Subject: [PATCH] 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> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- sound/usb/card.h | 1 + sound/usb/pcm.c | 2 +- sound/usb/quirks.c | 1 + sound/usb/stream.c | 1 + 4 files changed, 4 insertions(+), 1 deletion(-) -- 1.8.1.2