diff options
Diffstat (limited to 'drivers/firewire')
| -rw-r--r-- | drivers/firewire/core-transaction.c | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c index 673b03f8b4e..9882240205c 100644 --- a/drivers/firewire/core-transaction.c +++ b/drivers/firewire/core-transaction.c @@ -229,6 +229,23 @@ static void fw_fill_request(struct fw_packet *packet, int tcode, int tlabel, packet->payload_mapped = false; } +static int allocate_tlabel(struct fw_card *card) +{ + int tlabel; + + tlabel = card->current_tlabel; + while (card->tlabel_mask & (1ULL << tlabel)) { + tlabel = (tlabel + 1) & 0x3f; + if (tlabel == card->current_tlabel) + return -EBUSY; + } + + card->current_tlabel = (tlabel + 1) & 0x3f; + card->tlabel_mask |= 1ULL << tlabel; + + return tlabel; +} + /** * This function provides low-level access to the IEEE1394 transaction * logic. Most C programs would use either fw_read(), fw_write() or @@ -290,16 +307,13 @@ void fw_send_request(struct fw_card *card, struct fw_transaction *t, int tcode, spin_lock_irqsave(&card->lock, flags); - tlabel = card->current_tlabel; - if (card->tlabel_mask & (1ULL << tlabel)) { + tlabel = allocate_tlabel(card); + if (tlabel < 0) { spin_unlock_irqrestore(&card->lock, flags); callback(card, RCODE_SEND_ERROR, NULL, 0, callback_data); return; } - card->current_tlabel = (card->current_tlabel + 1) & 0x3f; - card->tlabel_mask |= (1ULL << tlabel); - t->node_id = destination_id; t->tlabel = tlabel; t->callback = callback; |