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| author |   Takashi Sakamoto <o-takashi@sakamocchi.jp> | 2014-04-25 22:45:27 +0900 |
|---|---|---|
| committer |   Takashi Iwai <tiwai@suse.de> | 2014-05-26 14:32:33 +0200 |
| commit | 9d59124cacf5d0a1e89aee83de6233bdf97afdb1 (patch) | |
| tree | c2d5db4b7b360f6d59562f05c5ec2ccc4d88b668 /sound/firewire | |
| parent | ALSA: bebob: Add support for M-Audio special Firewire series (diff) | |
| download | linux-dev-9d59124cacf5d0a1e89aee83de6233bdf97afdb1.tar.xz linux-dev-9d59124cacf5d0a1e89aee83de6233bdf97afdb1.zip | |
ALSA: bebob/firewire-lib: Add a quirk of wrong dbc in empty packet for M-Audio special Firewire series
M-Audio Firewire 1814 has a quirk, ProjectMix I/O also has. They transmit
empty packet with wrong value of dbc incremented by 8 at high sampling rate.
According to IEC 61883-1, this value should be the same as the one in
previous packet.
This commit adds a flag named as CIP_EMPTY_HAS_WRONG_DBC. With flag, the value
of dbc in empty packet is overwittern by an expected value.
This is an example of this quirk:
CIP Header 0 CIP Header 1 Payload size
010D0000 9004F759 210
010D0010 90040B59 210
010D0020 90042359 210
01020028 9004FFFF 2 <-
010D0030 90043759 210
010D0040 90044B59 210
010D0050 90046359 210
01020058 9004FFFF 2 <-
010D0060 90047759 210
010D0070 90048B59 210
010D0080 9004A359 210
01020088 9004FFFF 2 <-
010D0090 9004B759 210
010D00A0 9004CB59 210
010D00B0 9004E359 210
010200B8 9004FFFF 2 <-
010D00C0 9004F759 210
010D00D0 90040B59 210
010D00E0 90042359 210
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/firewire')
| -rw-r--r-- | sound/firewire/amdtp.c | 4 | ||||
| -rw-r--r-- | sound/firewire/amdtp.h | 3 | ||||
| -rw-r--r-- | sound/firewire/bebob/bebob_stream.c | 7 |
3 files changed, 14 insertions, 0 deletions
diff --git a/sound/firewire/amdtp.c b/sound/firewire/amdtp.c index 690c60828872..e573f253e39d 100644 --- a/sound/firewire/amdtp.c +++ b/sound/firewire/amdtp.c @@ -665,6 +665,10 @@ static void handle_in_packet(struct amdtp_stream *s, /* Check data block counter continuity */ data_block_counter = cip_header[0] & AMDTP_DBC_MASK; + if (data_blocks == 0 && (s->flags & CIP_EMPTY_HAS_WRONG_DBC) && + s->data_block_counter != UINT_MAX) + data_block_counter = s->data_block_counter; + if (((s->flags & CIP_SKIP_DBC_ZERO_CHECK) && data_block_counter == 0) || (s->data_block_counter == UINT_MAX)) { lost = false; diff --git a/sound/firewire/amdtp.h b/sound/firewire/amdtp.h index c79f058f1621..d8ee7b0e9386 100644 --- a/sound/firewire/amdtp.h +++ b/sound/firewire/amdtp.h @@ -27,6 +27,8 @@ * skipped for detecting discontinuity. * @CIP_SKIP_INIT_DBC_CHECK: Only for in-stream. The value of dbc in first * packet is not continuous from an initial value. + * @CIP_EMPTY_HAS_WRONG_DBC: Only for in-stream. The value of dbc in empty + * packet is wrong but the others are correct. */ enum cip_flags { CIP_NONBLOCKING = 0x00, @@ -37,6 +39,7 @@ enum cip_flags { CIP_WRONG_DBS = 0x10, CIP_SKIP_DBC_ZERO_CHECK = 0x20, CIP_SKIP_INIT_DBC_CHECK = 0x40, + CIP_EMPTY_HAS_WRONG_DBC = 0x80, }; /** diff --git a/sound/firewire/bebob/bebob_stream.c b/sound/firewire/bebob/bebob_stream.c index 2695b7899410..3e74d9b1e357 100644 --- a/sound/firewire/bebob/bebob_stream.c +++ b/sound/firewire/bebob/bebob_stream.c @@ -457,6 +457,13 @@ int snd_bebob_stream_init_duplex(struct snd_bebob *bebob) /* See comments in next function */ init_completion(&bebob->bus_reset); bebob->tx_stream.flags |= CIP_SKIP_INIT_DBC_CHECK; + /* + * At high sampling rate, M-Audio special firmware transmits empty + * packet with the value of dbc incremented by 8 but the others are + * valid to IEC 61883-1. + */ + if (bebob->maudio_special_quirk) + bebob->tx_stream.flags |= CIP_EMPTY_HAS_WRONG_DBC; err = amdtp_stream_init(&bebob->rx_stream, bebob->unit, AMDTP_OUT_STREAM, CIP_BLOCKING); |