diff options
authorJarod Wilson <>2008-03-07 01:43:01 -0500
committerStefan Richter <>2008-03-14 00:56:59 +0100
commit51f9dbef5be41f3ff6000c874741a3a357f9bad7 (patch)
parent11bf20ad028880a56689f086bfbabfd88b2af38b (diff)
firewire: fw-sbp2: set single-phase retry_limit
Per the SBP-2 specification, all SBP-2 target devices must have a BUSY_TIMEOUT register. Per the 1394-1995 specification, the retry_limt portion of the register should be set to 0x0 initially, and set on the target by a logged in initiator (i.e., a Linux host w/firewire controller(s)). Well, as it turns out, lots of devices these days have actually moved on to starting to implement SBP-3 compliance, which says that retry_limit should default to 0xf instead (yes, SBP-3 stomps directly on 1394-1995, oops). Prior to this change, the firewire driver stack didn't touch retry_limit, and any SBP-3 compliant device worked fine, while SBP-2 compliant ones were unable to retransmit when the host returned an ack_busy_X, which resulted in stalled out I/O, eventually causing the SCSI layer to give up and offline the device. The simple fix is for us to set retry_limit to 0xf in the register for all devices (which actually matches what the old ieee1394 stack did). Prior to this change, a hard disk behind an SBP-2 Prolific PL-3507 bridge chip would routinely encounter buffer I/O errors and wind up offlined by the SCSI layer. With this change, I've encountered zero I/O failures moving tens of GB of data around. Signed-off-by: Jarod Wilson <> Signed-off-by: Stefan Richter <>
1 files changed, 27 insertions, 4 deletions
diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c
index 03069a454c0..8bce569a7c5 100644
--- a/drivers/firewire/fw-sbp2.c
+++ b/drivers/firewire/fw-sbp2.c
@@ -173,6 +173,7 @@ struct sbp2_target {
#define SBP2_ORB_TIMEOUT 2000U /* Timeout in ms */
#define SBP2_ORB_NULL 0x80000000
+#define SBP2_RETRY_LIMIT 0xf /* 15 retries */
@@ -812,6 +813,30 @@ static void sbp2_target_put(struct sbp2_target *tgt)
kref_put(&tgt->kref, sbp2_release_target);
+static void
+complete_set_busy_timeout(struct fw_card *card, int rcode,
+ void *payload, size_t length, void *done)
+ complete(done);
+static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu)
+ struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
+ struct fw_transaction t;
+ static __be32 busy_timeout;
+ /* FIXME: we should try to set dual-phase cycle_limit too */
+ busy_timeout = cpu_to_be32(SBP2_RETRY_LIMIT);
+ fw_send_request(device->card, &t, TCODE_WRITE_QUADLET_REQUEST,
+ lu->tgt->node_id, lu->generation, device->max_speed,
+ sizeof(busy_timeout), complete_set_busy_timeout, &done);
+ wait_for_completion(&done);
static void sbp2_reconnect(struct work_struct *work);
static void sbp2_login(struct work_struct *work)
@@ -864,10 +889,8 @@ static void sbp2_login(struct work_struct *work)
fw_notify("%s: logged in to LUN %04x (%d retries)\n",
tgt->bus_id, lu->lun, lu->retries);
-#if 0
- /* FIXME: The linux1394 sbp2 does this last step. */
- sbp2_set_busy_timeout(scsi_id);
+ /* set appropriate retry limit(s) in BUSY_TIMEOUT register */
+ sbp2_set_busy_timeout(lu);
PREPARE_DELAYED_WORK(&lu->work, sbp2_reconnect);