Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=14dc992aa782f8759c6d117d4322db62f62600ce
Commit: 14dc992aa782f8759c6d117d4322db62f62600ce
Parent: 4dccd020d7ca5e673d7804cc4ff80fbf58d8a37e
Author: Stefan Richter <[EMAIL PROTECTED]>
AuthorDate: Sun Jan 20 01:25:31 2008 +0100
Committer: Stefan Richter <[EMAIL PROTECTED]>
CommitDate: Wed Jan 30 22:22:26 2008 +0100
firewire: fw-sbp2: try to increase reconnect_hold (speed up reconnection)
Ask the target to grant 4 seconds instead of the standard and minimum of
1 second window after bus reset for reconnection. This accelerates
reconnection if there are more than one targets on the bus: If a login
and inquiry to one target blocks the fw-sbp2 workqueue for more than 1s
after bus reset, we now still can reconnect to the other target.
Before that, fw-sbp2's reconnect attempts would be rejected with "error
status: 0:9" (function rejected), and fw-sbp2 would finally re-login.
All those futile reconnect attemps cost extra time until the target
which needs re-login is ready for I/O again.
The reconnect timeout field in the login ORB doesn't have to be honored
by the target though. I found that we could get up to
- allegedly 32768s from an old OXFW911 firmware
- 256s from LSI bridges
- 4s from OXUF922 and OXFW912 bridges,
- 2s from TI bridges,
- only the standard 1s from Initio and Prolific bridges and from
Apple OpenFirmware in target mode.
We just try to get 4 seconds which already covers the case of a few
HDDs on the same bus quite nicely.
A minor drawback occurs in the following (rare and impractical) border
case:
- two initiators are there, initiator 1 holds an exclusive login to
a target,
- initiator 1 goes off the bus,
- target refuses login attempts from initiator 2 until reconnect_hold
seconds after bus reset.
An alternative approach to the issue at hand would be to parallelize
fw-sbp2's reconnect and login work.
Signed-off-by: Stefan Richter <[EMAIL PROTECTED]>
Acked-by: Jarod Wilson <[EMAIL PROTECTED]>
---
drivers/firewire/fw-sbp2.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c
index 661a5b6..d2fbfc6 100644
--- a/drivers/firewire/fw-sbp2.c
+++ b/drivers/firewire/fw-sbp2.c
@@ -514,9 +514,10 @@ sbp2_send_management_orb(struct sbp2_logical_unit *lu, int
node_id,
orb->request.status_fifo.low = lu->address_handler.offset;
if (function == SBP2_LOGIN_REQUEST) {
+ /* Ask for 2^2 == 4 seconds reconnect grace period */
orb->request.misc |=
- MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login) |
- MANAGEMENT_ORB_RECONNECT(0);
+ MANAGEMENT_ORB_RECONNECT(2) |
+ MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login);
}
fw_memcpy_to_be32(&orb->request, &orb->request, sizeof(orb->request));
-
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