2012-10-19 01:24:47

by Joe Jin

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 <[email protected]>
Cc: Jitendra Kalsaria <[email protected]>
Cc: Ron Mercer <[email protected]>
---
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,
--
1.7.11.7

2012-10-19 17:12:34

by Jitendra Kalsaria

Subject: RE: [PATCH] qla3xxx: Ensure request/response queue addr writes to the registers

>From: Joe Jin [mailto:[email protected]]
>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 <[email protected]>
>Cc: Jitendra Kalsaria <[email protected]>
>Cc: Ron Mercer <[email protected]>
>---
> 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