[PATCH 0/2] Fix kernel crash and EEH recovery issues

[PATCH 0/2] Fix kernel crash and EEH recovery issues

[wenxiong]

The patches fix kernel crash and EEH recovery issues.

Thanks,
Wendy
-- 

[PATCH 1/2] bnx2x: Adapter not recovery from EEH error injection

[wenxiong]

[-- Attachment #1: bnx2x_eeh_fix --]
[-- Type: text/plain, Size: 985 bytes --]

When injecting EEH error to bnx2x adapter, adapter couldn't be recovery
and caused recursive EEH errors. The patch fixes the issue.

Signed-off-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
---
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
===================================================================
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c	2014-05-22 18:42:48.000000000 -0500
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c	2014-05-22 18:44:36.757765539 -0500
@@ -13279,8 +13279,8 @@ static int bnx2x_eeh_nic_unload(struct b
 	netdev_reset_tc(bp->dev);
 
 	del_timer_sync(&bp->timer);
-	cancel_delayed_work(&bp->sp_task);
-	cancel_delayed_work(&bp->period_task);
+	cancel_delayed_work_sync(&bp->sp_task);
+	cancel_delayed_work_sync(&bp->period_task);
 
 	spin_lock_bh(&bp->stats_lock);
 	bp->stats_state = STATS_STATE_DISABLED;

-- 

[PATCH 2/2] bnx2x: Fix kernel crash and data miscompare after EEH recovery

[wenxiong]

[-- Attachment #1: bnx2x_rmb_fix --]
[-- Type: text/plain, Size: 1247 bytes --]

A rmb() is required to ensure that the CQE is not read before it
is written by the adapter DMA.  PCI ordering rules will make sure
the other fields are written before the marker at the end of struct
eth_fast_path_rx_cqe but without rmb() a weakly ordered processor can
process stale data.

Without the barrier we have observed various crashes including
bnx2x_tpa_start being called on queues not stopped (resulting in message
start of bin not in stop) and NULL pointer exceptions from bnx2x_rx_int.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
---
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c |    2 ++
 1 file changed, 2 insertions(+)

Index: b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
===================================================================
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c	2014-05-23 10:34:21.000000000 -0500
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c	2014-05-23 10:35:39.277766585 -0500
@@ -906,6 +906,8 @@ static int bnx2x_rx_int(struct bnx2x_fas
 		bd_prod = RX_BD(bd_prod);
 		bd_cons = RX_BD(bd_cons);
 
+		rmb();
+
 		cqe_fp_flags = cqe_fp->type_error_flags;
 		cqe_fp_type = cqe_fp_flags & ETH_FAST_PATH_RX_CQE_TYPE;
 

-- 

Re: [PATCH 0/2] Fix kernel crash and EEH recovery issues

[David Miller]

From: wenxiong@linux.vnet.ibm.com
Date: Fri, 23 May 2014 11:29:55 -0500

> The patches fix kernel crash and EEH recovery issues.

Can you please have some courtesy and CC: the maintainers
of this driver when you submit fixes to it?

Also, all of that detailed explaination you put into patch #2
belongs also in a comment about the memory barrier in the code.

Every memory barrier should be clearly explained with a comment
especially when a non-SMP barrier is involved.