From 675398674c4edc2058a1dd632abd5d748b4653c3 Mon Sep 17 00:00:00 2001 From: Takashi Sakamoto Date: Sun, 14 Jun 2020 23:12:21 +0900 Subject: [PATCH] ALSA: firewire-motu: wait for notification when changing clock configuration for protocol v3 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 Link: https://lore.kernel.org/r/20200614141221.53527-1-o-takashi@sakamocchi.jp Signed-off-by: Takashi Iwai --- sound/firewire/motu/motu-protocol-v3.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/sound/firewire/motu/motu-protocol-v3.c b/sound/firewire/motu/motu-protocol-v3.c index 01a47ac7bb2d..4e6b0e449ee4 100644 --- a/sound/firewire/motu/motu-protocol-v3.c +++ b/sound/firewire/motu/motu-protocol-v3.c @@ -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;