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authorLinus Torvalds <torvalds@linux-foundation.org>2024-02-10 07:56:39 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2024-02-10 07:56:39 -0800
commita38ff5bbf9799dd944c762412aaebc54818407f5 (patch)
tree4a89dae3d71435e593fac78ea3e2f80900c7ac08
parent5a7ec87063c0fbb7706fdccb0cc890757da6f4a1 (diff)
parent7ed4380009e96d9e9c605e12822e987b35b05648 (diff)
downloadlwn-a38ff5bbf9799dd944c762412aaebc54818407f5.tar.gz
lwn-a38ff5bbf9799dd944c762412aaebc54818407f5.zip
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
-rw-r--r--drivers/firewire/core-card.c18
1 files changed, 17 insertions, 1 deletions
diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c
index 6ac5ff20a2fe..8aaa7fcb2630 100644
--- a/drivers/firewire/core-card.c
+++ b/drivers/firewire/core-card.c
@@ -429,7 +429,23 @@ static void bm_work(struct work_struct *work)
*/
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.