>From: Joe Jin [mailto:joe....@oracle.com] 
>Sent: Thursday, October 18, 2012 6:25 PM
>To: Ron Mercer; Dept-Eng Linux Driver; Jitendra Kalsaria; Joe Jin
>Cc: netdev; linux-kernel; Greg Marsden
>Subject: [PATCH] qla3xxx: Ensure request/response queue addr writes to the 
>registers
>
>Before use the request and response queue addr, make sure it has wrote
>to the registers.
>
>Signed-off-by: Joe Jin <joe....@oracle.com>
>Cc: Jitendra Kalsaria <jitendra.kalsa...@qlogic.com>
>Cc: Ron Mercer <ron.mer...@qlogic.com>
>---
> drivers/net/ethernet/qlogic/qla3xxx.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
>diff --git a/drivers/net/ethernet/qlogic/qla3xxx.c 
>b/drivers/net/ethernet/qlogic/qla3xxx.c
>index df09b1c..f745ade 100644
>--- a/drivers/net/ethernet/qlogic/qla3xxx.c
>+++ b/drivers/net/ethernet/qlogic/qla3xxx.c
>@@ -2525,6 +2525,12 @@ static int ql_alloc_net_req_rsp_queues(struct 
>ql3_adapter *qdev)
>       qdev->req_q_size =
>           (u32) (NUM_REQ_Q_ENTRIES * sizeof(struct ob_mac_iocb_req));
> 
>+      /*
>+       * The barrier is required to ensure request and response queue
>+       * addr writes to the registers.
>+       */
>+      wmb();
>+
>       qdev->req_q_virt_addr =
>           pci_alloc_consistent(qdev->pdev,
>                                (size_t) qdev->req_q_size,

Joe,

You need to move below line above the write memory barrier to get response 
queue address write to register
        qdev->rsp_q_size = NUM_RSP_Q_ENTRIES * sizeof(struct net_rsp_iocb);

Your patch will be like below:
<snip>
        qdev->req_q_size =
                (u32) (NUM_REQ_Q_ENTRIES * sizeof(struct ob_mac_iocb_req));

+       qdev->rsp_q_size = NUM_RSP_Q_ENTRIES * sizeof(struct net_rsp_iocb);
+
+       /*
+        * The barrier is required to ensure request and response queue
+        * addr writes to the registers.
+        */
+       wmb();
+

<\snip>


thanks,
        Jiten
-- 
1.7.11.7



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