2011-02-08 11:34:47

by Toshiharu Okada

Subject: [PATCH] pch_gbe: Fix the issue which a driver locks when rx offload is set by ethtool

This driver will be in a deadlock, When the rx offload is set by ethtool.
So, The pch_gbe_reinit_locked function was modified.

Signed-off-by: Toshiharu Okada <[email protected]>
---
drivers/net/pch_gbe/pch_gbe_main.c | 10 ++++------
1 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/net/pch_gbe/pch_gbe_main.c b/drivers/net/pch_gbe/pch_gbe_main.c
index 3248313..0e6922f 100644
--- a/drivers/net/pch_gbe/pch_gbe_main.c
+++ b/drivers/net/pch_gbe/pch_gbe_main.c
@@ -520,7 +520,9 @@ static void pch_gbe_reset_task(struct work_struct *work)
struct pch_gbe_adapter *adapter;
adapter = container_of(work, struct pch_gbe_adapter, reset_task);

+ rtnl_lock();
pch_gbe_reinit_locked(adapter);
+ rtnl_unlock();
}

/**
@@ -531,12 +533,8 @@ void pch_gbe_reinit_locked(struct pch_gbe_adapter *adapter)
{
struct net_device *netdev = adapter->netdev;

- rtnl_lock();
- if (netif_running(netdev)) {
- pch_gbe_down(adapter);
- pch_gbe_up(adapter);
- }
- rtnl_unlock();
+ pch_gbe_down(adapter);
+ pch_gbe_up(adapter);
}

/**
--
1.6.2.5

2011-02-09 00:39:56

by David Miller

Subject: Re: [PATCH] pch_gbe: Fix the issue which a driver locks when rx offload is set by ethtool

From: Toshiharu Okada <[email protected]>
Date: Tue, 08 Feb 2011 20:33:59 +0900

> @@ -531,12 +533,8 @@ void pch_gbe_reinit_locked(struct pch_gbe_adapter *adapter)
> {
> struct net_device *netdev = adapter->netdev;
>
> - rtnl_lock();
> - if (netif_running(netdev)) {
> - pch_gbe_down(adapter);
> - pch_gbe_up(adapter);
> - }
> - rtnl_unlock();
> + pch_gbe_down(adapter);
> + pch_gbe_up(adapter);

Are you sure you can just blindly delete the netif_running() check here?

2011-02-09 02:22:16

by Toshiharu Okada

Subject: Re: [PATCH] pch_gbe: Fix the issue which a driver locks when rx offload is set by ethtool

From: David Miller <[email protected]>
Date: Tue, 08 Feb 2011 16:40:30 -0800 (PST)

>> @@ -531,12 +533,8 @@ void pch_gbe_reinit_locked(struct pch_gbe_adapter
>> *adapter)
>> {
>> struct net_device *netdev = adapter->netdev;
>>
>> - rtnl_lock();
>> - if (netif_running(netdev)) {
>> - pch_gbe_down(adapter);
>> - pch_gbe_up(adapter);
>> - }
>> - rtnl_unlock();
>> + pch_gbe_down(adapter);
>> + pch_gbe_up(adapter);
>
>Are you sure you can just blindly delete the netif_running() check here?

Yes, sure.
pch_gbe_reinit_locked() is called after confirming of netif_running() except
for pch_gbe_reset_task() function.
This netif_running() was redundant.

Best regards
Toshiharu Okada(OKI semiconductor)

2011-02-09 06:56:28

by David Miller

Subject: Re: [PATCH] pch_gbe: Fix the issue which a driver locks when rx offload is set by ethtool

From: "Toshiharu Okada" <[email protected]>
Date: Wed, 9 Feb 2011 11:04:11 +0900

> From: David Miller <[email protected]>
> Date: Tue, 08 Feb 2011 16:40:30 -0800 (PST)
>
>>> @@ -531,12 +533,8 @@ void pch_gbe_reinit_locked(struct pch_gbe_adapter
>>> *adapter)
>>> {
>>> struct net_device *netdev = adapter->netdev;
>>>
>>> - rtnl_lock();
>>> - if (netif_running(netdev)) {
>>> - pch_gbe_down(adapter);
>>> - pch_gbe_up(adapter);
>>> - }
>>> - rtnl_unlock();
>>> + pch_gbe_down(adapter);
>>> + pch_gbe_up(adapter);
>>
>>Are you sure you can just blindly delete the netif_running() check here?
>
> Yes, sure.
> pch_gbe_reinit_locked() is called after confirming of netif_running() except
> for pch_gbe_reset_task() function.
> This netif_running() was redundant.

Thanks for explaining, applied, thank you.

2011-02-09 07:03:30

by David Miller

Subject: Re: [PATCH] pch_gbe: Fix the issue which a driver locks when rx offload is set by ethtool

From: David Miller <[email protected]>
Date: Tue, 08 Feb 2011 22:57:02 -0800 (PST)

> From: "Toshiharu Okada" <[email protected]>
> Date: Wed, 9 Feb 2011 11:04:11 +0900
>
>> From: David Miller <[email protected]>
>> Date: Tue, 08 Feb 2011 16:40:30 -0800 (PST)
>>
>>>> @@ -531,12 +533,8 @@ void pch_gbe_reinit_locked(struct pch_gbe_adapter
>>>> *adapter)
>>>> {
>>>> struct net_device *netdev = adapter->netdev;
>>>>
>>>> - rtnl_lock();
>>>> - if (netif_running(netdev)) {
>>>> - pch_gbe_down(adapter);
>>>> - pch_gbe_up(adapter);
>>>> - }
>>>> - rtnl_unlock();
>>>> + pch_gbe_down(adapter);
>>>> + pch_gbe_up(adapter);
>>>
>>>Are you sure you can just blindly delete the netif_running() check here?
>>
>> Yes, sure.
>> pch_gbe_reinit_locked() is called after confirming of netif_running() except
>> for pch_gbe_reset_task() function.
>> This netif_running() was redundant.
>
> Thanks for explaining, applied, thank you.

Actually, I had to revert, this patch introduces an obvious compiler warning:

drivers/net/pch_gbe/pch_gbe_main.c: In function 'pch_gbe_reinit_locked':
drivers/net/pch_gbe/pch_gbe_main.c:533:21: warning: unused variable 'netdev'

Sloppy build issues like this reflects very poorly upon the patch
submitter.