From 410cf2bd3dc6ec1ed9e1b36b25b9d7aa927ed14e Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Mon, 13 Dec 2010 14:56:02 +0100 Subject: firewire: use split transaction timeout only for split transactions Instead of starting the split transaction timeout timer when any request is submitted, start it only when the destination's ACK_PENDING has been received. This prevents us from using a timeout that is too short, and, if the controller's AT queue is emptying very slowly, from cancelling a packet that has not yet been sent. Signed-off-by: Clemens Ladisch Signed-off-by: Stefan Richter --- drivers/firewire/core-transaction.c | 45 ++++++++++++++++++++++++++----------- include/linux/firewire.h | 2 +- 2 files changed, 33 insertions(+), 14 deletions(-) diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c index 9e81cc54abd2..d00f8ce902cc 100644 --- a/drivers/firewire/core-transaction.c +++ b/drivers/firewire/core-transaction.c @@ -72,6 +72,15 @@ #define PHY_CONFIG_ROOT_ID(node_id) ((((node_id) & 0x3f) << 24) | (1 << 23)) #define PHY_IDENTIFIER(id) ((id) << 30) +/* returns 0 if the split timeout handler is already running */ +static int try_cancel_split_timeout(struct fw_transaction *t) +{ + if (t->is_split_transaction) + return del_timer(&t->split_timeout_timer); + else + return 1; +} + static int close_transaction(struct fw_transaction *transaction, struct fw_card *card, int rcode) { @@ -81,7 +90,7 @@ static int close_transaction(struct fw_transaction *transaction, spin_lock_irqsave(&card->lock, flags); list_for_each_entry(t, &card->transaction_list, link) { if (t == transaction) { - if (!del_timer(&t->split_timeout_timer)) { + if (!try_cancel_split_timeout(t)) { spin_unlock_irqrestore(&card->lock, flags); goto timed_out; } @@ -141,16 +150,28 @@ static void split_transaction_timeout_callback(unsigned long data) card->tlabel_mask &= ~(1ULL << t->tlabel); spin_unlock_irqrestore(&card->lock, flags); - card->driver->cancel_packet(card, &t->packet); - - /* - * At this point cancel_packet will never call the transaction - * callback, since we just took the transaction out of the list. - * So do it here. - */ t->callback(card, RCODE_CANCELLED, NULL, 0, t->callback_data); } +static void start_split_transaction_timeout(struct fw_transaction *t, + struct fw_card *card) +{ + unsigned long flags; + + spin_lock_irqsave(&card->lock, flags); + + if (list_empty(&t->link) || WARN_ON(t->is_split_transaction)) { + spin_unlock_irqrestore(&card->lock, flags); + return; + } + + t->is_split_transaction = true; + mod_timer(&t->split_timeout_timer, + jiffies + card->split_timeout_jiffies); + + spin_unlock_irqrestore(&card->lock, flags); +} + static void transmit_complete_callback(struct fw_packet *packet, struct fw_card *card, int status) { @@ -162,7 +183,7 @@ static void transmit_complete_callback(struct fw_packet *packet, close_transaction(t, card, RCODE_COMPLETE); break; case ACK_PENDING: - t->timestamp = packet->timestamp; + start_split_transaction_timeout(t, card); break; case ACK_BUSY_X: case ACK_BUSY_A: @@ -349,11 +370,9 @@ void fw_send_request(struct fw_card *card, struct fw_transaction *t, int tcode, t->node_id = destination_id; t->tlabel = tlabel; t->card = card; + t->is_split_transaction = false; setup_timer(&t->split_timeout_timer, split_transaction_timeout_callback, (unsigned long)t); - /* FIXME: start this timer later, relative to t->timestamp */ - mod_timer(&t->split_timeout_timer, - jiffies + card->split_timeout_jiffies); t->callback = callback; t->callback_data = callback_data; @@ -926,7 +945,7 @@ void fw_core_handle_response(struct fw_card *card, struct fw_packet *p) spin_lock_irqsave(&card->lock, flags); list_for_each_entry(t, &card->transaction_list, link) { if (t->node_id == source && t->tlabel == tlabel) { - if (!del_timer(&t->split_timeout_timer)) { + if (!try_cancel_split_timeout(t)) { spin_unlock_irqrestore(&card->lock, flags); goto timed_out; } diff --git a/include/linux/firewire.h b/include/linux/firewire.h index 1cd637ef62d2..9a3f5f9383f6 100644 --- a/include/linux/firewire.h +++ b/include/linux/firewire.h @@ -302,9 +302,9 @@ struct fw_packet { struct fw_transaction { int node_id; /* The generation is implied; it is always the current. */ int tlabel; - int timestamp; struct list_head link; struct fw_card *card; + bool is_split_transaction; struct timer_list split_timeout_timer; struct fw_packet packet; -- cgit v1.2.2