From: Andrew Vasquez <[email protected]>
There's a subtle race in the loop/bus-reset handling whereby a
VHA's loop-state can get incorrectly set to 'down' after the
loop-reset and firmware's completion of link re-negotiation. The
original code incorrectly assumes that firmware AENs would arrive
only after mailbox-command execution to initiate the link-flap.
Here's a good case with the old code (AENs arrive after
mailbox-command completion):
qla2xxx [0000:03:00.1]-8012:91: BUS RESET ISSUED nexus=91:0:4.
qla2xxx [0000:03:00.1]-287d:91: FCPort state transitioned from ONLINE
to LOST - portid=010100.
qla2xxx [0000:03:00.1]-580e:91: Asynchronous P2P MODE received.
qla2xxx [0000:03:00.1]-287d:91: FCPort state transitioned from ONLINE
to LOST - portid=010400.
qla2xxx [0000:03:00.1]-802b:91: BUS RESET SUCCEEDED nexus=91:0:4.
qla2xxx [0000:03:00.1]-480b:91: Reset marker scheduled.
qla2xxx [0000:03:00.1]-5812:91: Port database changed ffff 0006 0000.
qla2xxx [0000:03:00.1]-505f:91: Link is operational (4 Gbps).
qla2xxx [0000:03:00.1]-480c:91: Reset marker end.
qla2xxx [0000:03:00.1]-480f:91: Loop resync scheduled.
qla2xxx [0000:03:00.1]-8837:91: F/W Ready - OK.
qla2xxx [0000:03:00.1]-883a:91: fw_state=3 (7, 0, 0, 0) curr
time=170b8f315.
qla2xxx [0000:03:00.1]-280e:91: HBA in F P2P topology.
qla2xxx [0000:03:00.1]-2812:91: qla2x00_configure_hba success
qla2xxx [0000:03:00.1]-2814:91: Configure loop -- dpc flags = 0x5260.
notice how the 'Port database changed' (8014) arrived after the
bus-reset handler completed 'BUS RESET SUCCEEDED'.
Now, here's a failing case with the old code (AENs arrive before
mailbox-command completion):
qla2xxx [0000:03:00.1]-8012:91: BUS RESET ISSUED nexus=91:0:0.
qla2xxx [0000:03:00.1]-580e:91: Asynchronous P2P MODE received.
qla2xxx [0000:03:00.1]-287d:91: FCPort state transitioned from ONLINE
to LOST - portid=010100.
qla2xxx [0000:03:00.1]-287d:91: FCPort state transitioned from ONLINE
to LOST - portid=010400.
qla2xxx [0000:03:00.1]-4800:91: DPC handler sleeping.
qla2xxx [0000:03:00.1]-5812:91: Port database changed ffff 0006 0000.
qla2xxx [0000:03:00.1]-505f:91: Link is operational (4 Gbps).
qla2xxx [0000:03:00.1]-802b:91: BUS RESET SUCCEEDED nexus=91:0:0.
qla2xxx [0000:03:00.1]-480b:91: Reset marker scheduled.
qla2xxx [0000:03:00.1]-480c:91: Reset marker end.
qla2xxx [0000:03:00.1]-480f:91: Loop resync scheduled.
qla2xxx [0000:03:00.1]-8837:91: F/W Ready - OK.
qla2xxx [0000:03:00.1]-883a:91: fw_state=3 (7, 0, 0, 0) curr
time=170be9eb2.
qla2xxx [0000:03:00.1]-280e:91: HBA in F P2P topology.
qla2xxx [0000:03:00.1]-2812:91: qla2x00_configure_hba success
qla2xxx [0000:03:00.1]-2814:91: Configure loop -- dpc flags = 0x5260.
qla2xxx [0000:03:00.1]-281e:91: Needs RSCN update and loop transition.
qla2xxx [0000:03:00.1]-286a:91: qla2x00_configure_loop *** FAILED ***.
qla2xxx [0000:03:00.1]-4810:91: Loop resync end.
qla2xxx [0000:03:00.1]-4800:91: DPC handler sleeping.
This race would ultimately lead to devices go unexpectedly
offline until another link-flap or chip-reset would cause driver
re-discovery to take place.
Signed-off-by: Andrew Vasquez <[email protected]>
Signed-off-by: Saurav Kashyap <[email protected]>
---
drivers/scsi/qla2xxx/qla_os.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 2d2afdb..0612d25 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -1305,14 +1305,14 @@ qla2x00_loop_reset(scsi_qla_host_t *vha)
}
if (ha->flags.enable_lip_full_login && !IS_CNA_CAPABLE(ha)) {
+ atomic_set(&vha->loop_state, LOOP_DOWN);
+ atomic_set(&vha->loop_down_timer, LOOP_DOWN_TIME);
+ qla2x00_mark_all_devices_lost(vha, 0);
ret = qla2x00_full_login_lip(vha);
if (ret != QLA_SUCCESS) {
ql_dbg(ql_dbg_taskm, vha, 0x802d,
"full_login_lip=%d.\n", ret);
}
- atomic_set(&vha->loop_state, LOOP_DOWN);
- atomic_set(&vha->loop_down_timer, LOOP_DOWN_TIME);
- qla2x00_mark_all_devices_lost(vha, 0);
}
if (ha->flags.enable_lip_reset) {
--
1.7.7
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
