Currently, when waiting for a response, callers can start another transaction by scheduling another tasklet. This is not good for error processing.
This commit serialize request/response transactions, by adding one boolean member to represent idling state.
Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp --- sound/firewire/lib.c | 8 ++++++++ sound/firewire/lib.h | 1 + 2 files changed, 9 insertions(+)
diff --git a/sound/firewire/lib.c b/sound/firewire/lib.c index f5b5526..a66e011 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_tasklet(unsigned long data) @@ -86,6 +88,10 @@ static void midi_port_tasklet(unsigned long data) int generation; int type;
+ /* Under transacting. */ + if (!port->idling) + return; + /* Nothing to do. */ if (substream == NULL || snd_rawmidi_transmit_empty(substream)) return; @@ -110,6 +116,7 @@ static void midi_port_tasklet(unsigned long data) type = TCODE_WRITE_BLOCK_REQUEST;
/* Start this transaction. */ + port->idling = false; generation = port->parent->generation; smp_rmb(); /* node_id vs. generation */ fw_send_request(port->parent->card, &port->transaction, type, @@ -142,6 +149,7 @@ int snd_fw_async_midi_port_init(struct snd_fw_async_midi_port *port, port->parent = fw_parent_device(unit); port->addr = addr; port->packetize = packetize; + port->idling = true;
tasklet_init(&port->tasklet, midi_port_tasklet, (unsigned long)port);
diff --git a/sound/firewire/lib.h b/sound/firewire/lib.h index c662bf9..9d76f5c 100644 --- a/sound/firewire/lib.h +++ b/sound/firewire/lib.h @@ -25,6 +25,7 @@ static inline bool rcode_is_permanent_error(int rcode) struct snd_fw_async_midi_port { struct fw_device *parent; struct tasklet_struct tasklet; + bool idling;
__u64 addr; struct fw_transaction transaction;