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authorTakashi Sakamoto <o-takashi@sakamocchi.jp>2019-10-18 09:19:11 +0300
committerTakashi Iwai <tiwai@suse.de>2019-10-19 10:18:27 +0300
commitacfedcbe1ce4c69e1da914f39c02d945c80198d4 (patch)
tree83adb14a072f8f13db5516c55f2b8c6458ce626c /sound/firewire/fireface
parent60dd49298ec5803ca423836d5a724c3fe402cc3f (diff)
downloadlinux-acfedcbe1ce4c69e1da914f39c02d945c80198d4.tar.xz
ALSA: firewire-lib: postpone to start IR context
Some devices have a quirk to postpone transmission of isoc packet for several dozen or hundred isoc cycles since configured to transmit. Furthermore, some devices have a quirk to transmit isoc packet with discontinued data of its header. In 1394 OHCI specification, software allows to start isoc context with certain isoc cycle. Linux firewire subsystem has kernel API to use it as well. This commit uses the functionality of 1394 OHCI controller to handle the quirks. At present, this feature is convenient to ALSA bebob and fireface driver. As a result, some devices can be safely handled, as long as I know: - MAudio FireWire solo - MAudio ProFire Lightbridge - MAudio FireWire 410 - Roland FA-66 Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Link: https://lore.kernel.org/r/20191018061911.24909-7-o-takashi@sakamocchi.jp Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/firewire/fireface')
-rw-r--r--sound/firewire/fireface/ff-stream.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/sound/firewire/fireface/ff-stream.c b/sound/firewire/fireface/ff-stream.c
index a13754f914e8..63b79c4a5405 100644
--- a/sound/firewire/fireface/ff-stream.c
+++ b/sound/firewire/fireface/ff-stream.c
@@ -184,6 +184,7 @@ int snd_ff_stream_start_duplex(struct snd_ff *ff, unsigned int rate)
*/
if (!amdtp_stream_running(&ff->rx_stream)) {
int spd = fw_parent_device(ff->unit)->max_speed;
+ unsigned int ir_delay_cycle;
err = ff->spec->protocol->begin_session(ff, rate);
if (err < 0)
@@ -199,7 +200,14 @@ int snd_ff_stream_start_duplex(struct snd_ff *ff, unsigned int rate)
if (err < 0)
goto error;
- err = amdtp_domain_start(&ff->domain);
+ // The device postpones start of transmission mostly for several
+ // cycles after receiving packets firstly.
+ if (ff->spec->protocol == &snd_ff_protocol_ff800)
+ ir_delay_cycle = 800; // = 100 msec
+ else
+ ir_delay_cycle = 16; // = 2 msec
+
+ err = amdtp_domain_start(&ff->domain, ir_delay_cycle);
if (err < 0)
goto error;