diff options
Diffstat (limited to 'drivers/firewire/core-card.c')
| -rw-r--r-- | drivers/firewire/core-card.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c index 8aaa7fcb2..401a77e3b 100644 --- a/drivers/firewire/core-card.c +++ b/drivers/firewire/core-card.c @@ -500,7 +500,19 @@ static void bm_work(struct work_struct *work) fw_notice(card, "phy config: new root=%x, gap_count=%d\n", new_root_id, gap_count); fw_send_phy_config(card, new_root_id, generation, gap_count); - reset_bus(card, true); + /* + * Where possible, use a short bus reset to minimize + * disruption to isochronous transfers. But in the event + * of a gap count inconsistency, use a long bus reset. + * + * As noted in 1394a 8.4.6.2, nodes on a mixed 1394/1394a bus + * may set different gap counts after a bus reset. On a mixed + * 1394/1394a bus, a short bus reset can get doubled. Some + * nodes may treat the double reset as one bus reset and others + * may treat it as two, causing a gap count inconsistency + * again. Using a long bus reset prevents this. + */ + reset_bus(card, card->gap_count != 0); /* Will allocate broadcast channel after the reset. */ goto out; } |