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Commit 410cf2bd authored by Clemens Ladisch's avatar Clemens Ladisch Committed by Stefan Richter
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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: default avatarClemens Ladisch <clemens@ladisch.de>
Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
parent 693a50b5

drivers/firewire/core-transaction.c

+32 −13
Original line number Diff line number Diff line
@@ -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;

			}

include/linux/firewire.h

+1 −1
Original line number Diff line number Diff line
@@ -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;