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ALSA: firewire-motu: wait for notification when changing clock configuration for protocol v3

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It costs expensive to change clock configuration for models of protocol
version 3. In current implementation, speculative strategy is used to
finish the operation; just waiting for 4 seconds. As long as I investigate,
when accepting and changing clock status actually, the device sends
notification with mask.

This commit uses wise way to wait for the notification after changing
sampling clock rate during 4 seconds.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20200614141221.53527-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Sakamoto 2020-06-14 23:12:21 +09:00 committed by Takashi Iwai
parent d9d52398b7
commit 675398674c
1 changed files with 13 additions and 3 deletions
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16
sound/firewire/motu/motu-protocol-v3.c
View file

@ -24,6 +24,9 @@
#define V3_NO_ADAT_OPT_OUT_IFACE_A 0x00040000
#define V3_NO_ADAT_OPT_OUT_IFACE_B 0x00400000
#define V3_MSG_FLAG_CLK_CHANGED 0x00000002
#define V3_CLK_WAIT_MSEC 4000
int snd_motu_protocol_v3_get_clock_rate(struct snd_motu *motu,
unsigned int *rate)
{
@ -79,9 +82,16 @@ int snd_motu_protocol_v3_set_clock_rate(struct snd_motu *motu,
return err;
if (need_to_wait) {
/* Cost expensive. */
if (msleep_interruptible(4000) > 0)
return -EINTR;
int result;
motu->msg = 0;
result = wait_event_interruptible_timeout(motu->hwdep_wait,
motu->msg & V3_MSG_FLAG_CLK_CHANGED,
msecs_to_jiffies(V3_CLK_WAIT_MSEC));
if (result < 0)
return result;
if (result == 0)
return -ETIMEDOUT;
}
return 0;