Merge tag 'firewire-fixes-6.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394

Pull firewire fix from Takashi Sakamoto:
"A change to accelerate the device detection step in some cases.

In the self-identification step after bus-reset, all nodes in the same
bus broadcast selfID packet including the value of gap count. The
value is related to the cable hops between nodes, and used to
calculate the subaction gap and the arbitration reset gap.

When each node has the different value of the gap count, the
asynchronous communication between them is unreliable, since an
asynchronous transaction could be interrupted by another asynchronous
transaction before completion. The gap count inconsistency can be
resolved by several ways; e.g. the transfer of PHY configuration
packet and generation of bus-reset.

The current implementation of firewire stack can correctly detect the
gap count inconsistency, however the recovery action from the
inconsistency tends to be delayed after reading configuration ROM of
root node. This results in the long time to probe devices in some
combinations of hardware.

Here the stack is changed to schedule the action as soon as possible"

* tag 'firewire-fixes-6.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
firewire: core: send bus reset promptly on gap count error

drivers/firewire/core-card.c

···
 	 */
 	card->bm_generation = generation;
 
-	if (root_device == NULL) {
+	if (card->gap_count == 0) {
+		/*
+		 * If self IDs have inconsistent gap counts, do a
+		 * bus reset ASAP. The config rom read might never
+		 * complete, so don't wait for it. However, still
+		 * send a PHY configuration packet prior to the
+		 * bus reset. The PHY configuration packet might
+		 * fail, but 1394-2008 8.4.5.2 explicitly permits
+		 * it in this case, so it should be safe to try.
+		 */
+		new_root_id = local_id;
+		/*
+		 * We must always send a bus reset if the gap count
+		 * is inconsistent, so bypass the 5-reset limit.
+		 */
+		card->bm_retries = 0;
+	} else if (root_device == NULL) {
 		/*
 		 * Either link_on is false, or we failed to read the
 		 * config rom.  In either case, pick another root.