[dpdk-dev] [PATCH v2] ixgbe: fix occasional timeouts when starting VF

[Bernard Iremonger]

Increase the polling wait time from 10 milleseconds to 15.

Fixes: af75078fece3 ("first public release")

Signed-off-by: Bernard Iremonger 

---
Change in v2:
added fixes line

---
 drivers/net/ixgbe/ixgbe_rxtx.c | 6 +++---
 drivers/net/ixgbe/ixgbe_rxtx.h | 3 ++-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c b/drivers/net/ixgbe/ixgbe_rxtx.c
index b018ba7..4ad947f 100644
--- a/drivers/net/ixgbe/ixgbe_rxtx.c
+++ b/drivers/net/ixgbe/ixgbe_rxtx.c
@@ -1,7 +1,7 @@
 /*-
  *   BSD LICENSE
  *
- *   Copyright(c) 2010-2015 Intel Corporation. All rights reserved.
+ *   Copyright(c) 2010-2016 Intel Corporation. All rights reserved.
  *   Copyright 2014 6WIND S.A.
  *   All rights reserved.
  *
@@ -4961,7 +4961,7 @@ ixgbevf_dev_rxtx_start(struct rte_eth_dev *dev)
txdctl |= IXGBE_TXDCTL_ENABLE;
IXGBE_WRITE_REG(hw, IXGBE_VFTXDCTL(i), txdctl);

-   poll_ms = 10;
+   poll_ms = RTE_IXGBE_REGISTER_POLL_WAIT_15_MS;
/* Wait until TX Enable ready */
do {
rte_delay_ms(1);
@@ -4979,7 +4979,7 @@ ixgbevf_dev_rxtx_start(struct rte_eth_dev *dev)
IXGBE_WRITE_REG(hw, IXGBE_VFRXDCTL(i), rxdctl);

/* Wait until RX Enable ready */
-   poll_ms = 10;
+   poll_ms = RTE_IXGBE_REGISTER_POLL_WAIT_15_MS;
do {
rte_delay_ms(1);
rxdctl = IXGBE_READ_REG(hw, IXGBE_VFRXDCTL(i));
diff --git a/drivers/net/ixgbe/ixgbe_rxtx.h b/drivers/net/ixgbe/ixgbe_rxtx.h
index f9e708f..8085cf4 100644
--- a/drivers/net/ixgbe/ixgbe_rxtx.h
+++ b/drivers/net/ixgbe/ixgbe_rxtx.h
@@ -1,7 +1,7 @@
 /*-
  *   BSD LICENSE
  *
- *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   Copyright(c) 2010-2016 Intel Corporation. All rights reserved.
  *   All rights reserved.
  *
  *   Redistribution and use in source and binary forms, with or without
@@ -77,6 +77,7 @@
 #endif

 #define RTE_IXGBE_REGISTER_POLL_WAIT_10_MS  10
+#define RTE_IXGBE_REGISTER_POLL_WAIT_15_MS  15
 #define RTE_IXGBE_WAIT_100_US   100
 #define RTE_IXGBE_VMTXSW_REGISTER_COUNT 2

-- 
2.6.3

[dpdk-dev] [PATCH v2] ixgbe: fix occasional timeouts when starting VF

[Thomas Monjalon]

2016-04-05 15:55, Bernard Iremonger:
> - poll_ms = 10;
> + poll_ms = RTE_IXGBE_REGISTER_POLL_WAIT_15_MS;
[...]
>  #define RTE_IXGBE_REGISTER_POLL_WAIT_10_MS  10
> +#define RTE_IXGBE_REGISTER_POLL_WAIT_15_MS  15
>  #define RTE_IXGBE_WAIT_100_US   100

I don't understand why these constants are needed.
There is no semantic, just an arbitrary number.

[dpdk-dev] [PATCH v2] ixgbe: fix occasional timeouts when starting VF

[Iremonger, Bernard]

Hi Thomas,

> -Original Message-
> From: Thomas Monjalon [mailto:thomas.monjalon at 6wind.com]
> Sent: Tuesday, April 5, 2016 4:48 PM
> To: Iremonger, Bernard 
> Cc: dev at dpdk.org; Lu, Wenzhuo 
> Subject: Re: [dpdk-dev] [PATCH v2] ixgbe: fix occasional timeouts when
> starting VF
> 
> 2016-04-05 15:55, Bernard Iremonger:
> > -   poll_ms = 10;
> > +   poll_ms = RTE_IXGBE_REGISTER_POLL_WAIT_15_MS;
> [...]
> >  #define RTE_IXGBE_REGISTER_POLL_WAIT_10_MS  10
> > +#define RTE_IXGBE_REGISTER_POLL_WAIT_15_MS  15
> >  #define RTE_IXGBE_WAIT_100_US   100
> 
> I don't understand why these constants are needed.
> There is no semantic, just an arbitrary number.

I am seeing intermittent failures in the following test at line 4969 in 
ixgbe_rxtx.c:

while (--poll_ms && !(txdctl & IXGBE_TXDCTL_ENABLE))

Increasing the value of poll_ms does not address the root cause of this failure.
This needs more investigation.

Self NAK.