ALSA: fireworks: Add command/response functionality into hwdep interface

[firefly-linux-kernel-4.4.55.git] / sound / firewire / fireworks / fireworks_command.c

diff --git a/sound/firewire/fireworks/fireworks_command.c b/sound/firewire/fireworks/fireworks_command.c
index d5ea7051ad0caa7a0ea04540c1a66cc9af4ce746..166f80584c2a923da199990ca0b1920f646e52a0 100644 (file)
--- a/sound/firewire/fireworks/fireworks_command.c
+++ b/sound/firewire/fireworks/fireworks_command.c
@@ -22,7 +22,8 @@
  * Information commands. But this module don't use them.
  */
 
-#define EFW_TRANSACTION_SEQNUM_MAX     ((u32)~0)
+#define KERNEL_SEQNUM_MIN      (SND_EFW_TRANSACTION_USER_SEQNUM_MAX + 2)
+#define KERNEL_SEQNUM_MAX      ((u32)~0)
 
 /* for clock source and sampling rate */
 struct efc_clock {
@@ -120,8 +121,9 @@ efw_transaction(struct snd_efw *efw, unsigned int category,
 
        /* to keep consistency of sequence number */
        spin_lock(&efw->lock);
-       if (efw->seqnum + 2 >= EFW_TRANSACTION_SEQNUM_MAX)
-               efw->seqnum = 0;
+       if ((efw->seqnum < KERNEL_SEQNUM_MIN) ||
+           (efw->seqnum >= KERNEL_SEQNUM_MAX - 2))
+               efw->seqnum = KERNEL_SEQNUM_MIN;
        else
                efw->seqnum += 2;
        seqnum = efw->seqnum;