diff options
Diffstat (limited to 'sound/usb/pcm.c')
| -rw-r--r-- | sound/usb/pcm.c | 32 |
1 files changed, 31 insertions, 1 deletions
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index e3c5bc0df69d..9245f52d43bd 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -1409,6 +1409,32 @@ static void copy_to_urb(struct snd_usb_substream *subs, struct urb *urb, subs->hwptr_done -= runtime->buffer_size * stride; } +static unsigned int copy_to_urb_quirk(struct snd_usb_substream *subs, + struct urb *urb, int stride, + unsigned int bytes) +{ + __le32 packet_length; + int i; + + /* Put __le32 length descriptor at start of each packet. */ + for (i = 0; i < urb->number_of_packets; i++) { + unsigned int length = urb->iso_frame_desc[i].length; + unsigned int offset = urb->iso_frame_desc[i].offset; + + packet_length = cpu_to_le32(length); + offset += i * sizeof(packet_length); + urb->iso_frame_desc[i].offset = offset; + urb->iso_frame_desc[i].length += sizeof(packet_length); + memcpy(urb->transfer_buffer + offset, + &packet_length, sizeof(packet_length)); + copy_to_urb(subs, urb, offset + sizeof(packet_length), + stride, length); + } + /* Adjust transfer size accordingly. */ + bytes += urb->number_of_packets * sizeof(packet_length); + return bytes; +} + static void prepare_playback_urb(struct snd_usb_substream *subs, struct urb *urb) { @@ -1488,7 +1514,11 @@ static void prepare_playback_urb(struct snd_usb_substream *subs, subs->hwptr_done -= runtime->buffer_size * stride; } else { /* usual PCM */ - copy_to_urb(subs, urb, 0, stride, bytes); + if (!subs->tx_length_quirk) + copy_to_urb(subs, urb, 0, stride, bytes); + else + bytes = copy_to_urb_quirk(subs, urb, stride, bytes); + /* bytes is now amount of outgoing data */ } /* update delay with exact number of samples queued */ |