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authorTakashi Sakamoto <o-takashi@sakamocchi.jp>2015-10-09 08:10:26 +0900
committerTakashi Iwai <tiwai@suse.de>2015-10-09 09:57:05 +0200
commitd3ef9cb93aec59eb1d90d01ae0642fd517c25381 (patch)
treeab00c5e5d1c4ce2b0b12a2614e229d78b806aff6 /sound/firewire
parent585d7cba5e1fcd8703a120042f35695165986b9b (diff)
ALSA: firewire-lib: add a restriction for a transaction at once
Currently, when waiting for a response, callers can start another transaction by scheduling another work. This is not good for error processing of transaction, especially the first response is too late. This commit serialize request/response transactions, by adding one boolean member to represent idling state. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/firewire')
-rw-r--r--sound/firewire/lib.c9
-rw-r--r--sound/firewire/lib.h1
2 files changed, 10 insertions, 0 deletions
diff --git a/sound/firewire/lib.c b/sound/firewire/lib.c
index 03ada3f1047a..ddc3e88ee0d1 100644
--- a/sound/firewire/lib.c
+++ b/sound/firewire/lib.c
@@ -76,6 +76,8 @@ static void async_midi_port_callback(struct fw_card *card, int rcode,
if (rcode == RCODE_COMPLETE && substream != NULL)
snd_rawmidi_transmit_ack(substream, port->consume_bytes);
+
+ port->idling = true;
}
static void midi_port_work(struct work_struct *work)
@@ -86,6 +88,10 @@ static void midi_port_work(struct work_struct *work)
int generation;
int type;
+ /* Under transacting. */
+ if (!port->idling)
+ return;
+
/* Nothing to do. */
if (substream == NULL || snd_rawmidi_transmit_empty(substream))
return;
@@ -110,6 +116,8 @@ static void midi_port_work(struct work_struct *work)
type = TCODE_WRITE_BLOCK_REQUEST;
/* Start this transaction. */
+ port->idling = false;
+
/*
* In Linux FireWire core, when generation is updated with memory
* barrier, node id has already been updated. In this module, After
@@ -150,6 +158,7 @@ int snd_fw_async_midi_port_init(struct snd_fw_async_midi_port *port,
port->parent = fw_parent_device(unit);
port->addr = addr;
port->fill = fill;
+ port->idling = true;
INIT_WORK(&port->work, midi_port_work);
diff --git a/sound/firewire/lib.h b/sound/firewire/lib.h
index 37a7fe4235f2..0af06f44e8c2 100644
--- a/sound/firewire/lib.h
+++ b/sound/firewire/lib.h
@@ -30,6 +30,7 @@ typedef int (*snd_fw_async_midi_port_fill)(
struct snd_fw_async_midi_port {
struct fw_device *parent;
struct work_struct work;
+ bool idling;
u64 addr;
struct fw_transaction transaction;