Acked-by: Saurav Kashyap <saurav.kash...@qlogic.com>

Thanks,
~Saurav


>Lockdep reports:
>
>=== [ cut here ] ===
> =========================================================
> [ INFO: possible irq lock inversion dependency detected ]
> 3.6.0-0.0.0.28.36b5ec9-default #1 Not tainted
> ---------------------------------------------------------
> qla2xxx_1_dpc/368 just changed the state of lock:
>  (&(&ha->vport_slock)->rlock){+.....}, at: [<ffffffffa009b377>]
>qla2x00_configure_hba+0x197/0x3c0 [qla2xxx]
> but this lock was taken by another, HARDIRQ-safe lock in the past:
>  (&(&ha->hardware_lock)->rlock){-.....}
>
>and interrupts could create inverse lock ordering between them.
>
>other info that might help us debug this:
> Possible interrupt unsafe locking scenario:
>
>       CPU0                    CPU1
>       ----                    ----
>  lock(&(&ha->vport_slock)->rlock);
>                               local_irq_disable();
>                               lock(&(&ha->hardware_lock)->rlock);
>                               lock(&(&ha->vport_slock)->rlock);
>  <Interrupt>
>    lock(&(&ha->hardware_lock)->rlock);
>=== [ cut here ] ===
>
>Fix the potential deadlock by disabling IRQs while holding
>ha->vport_slock.
>
>Reported-and-tested-by: Srivatsa S. Bhat
><srivatsa.b...@linux.vnet.ibm.com>
>Signed-off-by: Jiri Kosina <jkos...@suse.cz>
>---
> drivers/scsi/qla2xxx/qla_init.c |    5 +++--
> 1 files changed, 3 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/scsi/qla2xxx/qla_init.c
>b/drivers/scsi/qla2xxx/qla_init.c
>index 799a58b..48fca47 100644
>--- a/drivers/scsi/qla2xxx/qla_init.c
>+++ b/drivers/scsi/qla2xxx/qla_init.c
>@@ -2080,6 +2080,7 @@ qla2x00_configure_hba(scsi_qla_host_t *vha)
>       uint8_t       domain;
>       char            connect_type[22];
>       struct qla_hw_data *ha = vha->hw;
>+      unsigned long flags;
>
>       /* Get host addresses. */
>       rval = qla2x00_get_adapter_id(vha,
>@@ -2154,9 +2155,9 @@ qla2x00_configure_hba(scsi_qla_host_t *vha)
>       vha->d_id.b.area = area;
>       vha->d_id.b.al_pa = al_pa;
>
>-      spin_lock(&ha->vport_slock);
>+      spin_lock_irqsave(&ha->vport_slock, flags);
>       qlt_update_vp_map(vha, SET_AL_PA);
>-      spin_unlock(&ha->vport_slock);
>+      spin_unlock_irqrestore(&ha->vport_slock, flags);
>
>       if (!vha->flags.init_done)
>               ql_log(ql_log_info, vha, 0x2010,
>
>--
>Jiri Kosina
>SUSE Labs
>--
>To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
>the body of a message to majord...@vger.kernel.org
>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>


This message and any attached documents contain information from QLogic 
Corporation or its wholly-owned subsidiaries that may be confidential. If you 
are not the intended recipient, you may not read, copy, distribute, or use this 
information. If you have received this transmission in error, please notify the 
sender immediately by reply e-mail and then delete this message.

--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to