Stanton SCS.1d uses Oxford Semiconductor FW 971 ASIC (FW971) for communication. Although the unit is bound to ALSA oxfw driver, the instance of sound card can not be added due to its quirk of plug information. This bug was added when snd-scs1x is merged into snd-oxfw at commit 9e2004f9cedf ("ALSA: oxfw: obsolete scs1x module").
This commit fixes the driver for the quirk. In cases that the unit returns NOT IMPLEMENTED for some AV/C commands, the sound card is added without any PCM/MIDI interfaces for packet streaming. For SCS.1d, model dependent operation adds MIDI interface and applications can use it to operate according to HSS1394 protocol from reverse-engineering work by Sean M. Pappalardo.
Plug Control Register (PCR) has information that the unit has a pair of plugs for isochronous communication:
(oMPR) $ ./firewire-request /dev/fw1 read 0xfffff0000900 result: 80ff0001 (iMPR) $ ./firewire-request /dev/fw1 read 0xfffff0000980 result: 80ff0001
AV/C PLUG INFO also returns information that the unit has a pair of plugs for isochronous communication.
(AV/C PLUG INFO command) $ ./firewire-request /dev/fw1 fcp 0x01ff0200ffffffff response: 000: 0c ff 02 00 01 01 02 02
However, AV/C PLUG SIGNAL INFO command is rejected for both plugs.
(AV/C OUTPUT PLUG SIGNAL INFO command) $ ./firewire-request /dev/fw1 fcp 0x01ff1800ffffffff response: 000: 0a ff 18 00 ff ff ff ff (AV/C INPUT PLUG SIGNAL INFO command) $ ./firewire-request /dev/fw1 fcp 0x01ff1900ffffffff response: 000: 0a ff 19 00 ff ff ff ff
Furthermore, AV/C EXTENDED STREAM FORMAT INFO is not implemented.
(AV/C EXTENDED STREAM FORMAT INFO list subfunction for input plug) $ ./firewire-request /dev/fw1 fcp 0x01ffbfc000000000ffff00ff response: 000: 08 ff bf c0 00 00 00 00 ff ff 00 ff (AV/C EXTENDED STREAM FORMAT INFO list subfunction for output plug) $ ./firewire-request /dev/fw1 fcp 0x01ffbfc001000000ffff00ff response: 000: 08 ff bf c0 01 00 00 00 ff ff 00 ff (AV/C EXTENDED STREAM FORMAT INFO single subfunction for input plug) $ ./firewire-request /dev/fw1 fcp 0x01ffbfc100000000ffffffff response: 000: 08 ff bf c1 00 00 00 00 ff ff ff ff (AV/C EXTENDED STREAM FORMAT INFO single subfunction for output plug) $ ./firewire-request /dev/fw1 fcp 0x01ffbfc101000000ffffffff response: 000: 08 ff bf c1 01 00 00 00 ff ff ff ff
Reference: https://mailman.alsa-project.org/pipermail/alsa-devel/2012-May/052264.html Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp --- sound/firewire/oxfw/oxfw-stream.c | 72 ++++++++++++++++++------------- 1 file changed, 42 insertions(+), 30 deletions(-)
diff --git a/sound/firewire/oxfw/oxfw-stream.c b/sound/firewire/oxfw/oxfw-stream.c index 36c3dd84d189..80c9dc13f1b5 100644 --- a/sound/firewire/oxfw/oxfw-stream.c +++ b/sound/firewire/oxfw/oxfw-stream.c @@ -735,45 +735,57 @@ int snd_oxfw_stream_discover(struct snd_oxfw *oxfw) /* use oPCR[0] if exists */ if (plugs[1] > 0) { err = fill_stream_formats(oxfw, AVC_GENERAL_PLUG_DIR_OUT, 0); - if (err < 0) - goto end; + if (err < 0) { + if (err != -ENXIO) + return err;
- for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) { - format = oxfw->tx_stream_formats[i]; - if (format == NULL) - continue; - err = snd_oxfw_stream_parse_format(format, &formation); - if (err < 0) - continue; - - /* Add one MIDI port. */ - if (formation.midi > 0) - oxfw->midi_input_ports = 1; - } + // The oPCR is not available for isoc communication. + err = 0; + } else { + for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) { + format = oxfw->tx_stream_formats[i]; + if (format == NULL) + continue; + err = snd_oxfw_stream_parse_format(format, + &formation); + if (err < 0) + continue; + + /* Add one MIDI port. */ + if (formation.midi > 0) + oxfw->midi_input_ports = 1; + }
- oxfw->has_output = true; + oxfw->has_output = true; + } }
/* use iPCR[0] if exists */ if (plugs[0] > 0) { err = fill_stream_formats(oxfw, AVC_GENERAL_PLUG_DIR_IN, 0); - if (err < 0) - goto end; + if (err < 0) { + if (err != -ENXIO) + return err;
- for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) { - format = oxfw->rx_stream_formats[i]; - if (format == NULL) - continue; - err = snd_oxfw_stream_parse_format(format, &formation); - if (err < 0) - continue; - - /* Add one MIDI port. */ - if (formation.midi > 0) - oxfw->midi_output_ports = 1; - } + // The iPCR is not available for isoc communication. + err = 0; + } else { + for (i = 0; i < SND_OXFW_STREAM_FORMAT_ENTRIES; i++) { + format = oxfw->rx_stream_formats[i]; + if (format == NULL) + continue; + err = snd_oxfw_stream_parse_format(format, + &formation); + if (err < 0) + continue; + + /* Add one MIDI port. */ + if (formation.midi > 0) + oxfw->midi_output_ports = 1; + }
- oxfw->has_input = true; + oxfw->has_input = true; + } } end: return err;