[PATCH] net: implement dev_disable_lro() hw_features compatibility

[PATCH] net: implement dev_disable_lro() hw_features compatibility

[Michał Mirosław]

Implement compatibility with new hw_features for dev_disable_lro().
This is a transition path - dev_disable_lro() should be later
integrated into netdev_fix_features() after all drivers are converted.

There's no point in exporting __ethtool_set_flags() as it and dev_disable_lro()
are always built-in.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
---

Patch is build-tested only, as I don't have any LRO-capable hardware.
It might be prettier to move dev_disable_lro() to ethtool.c.

 net/core/dev.c     |   20 ++++++++++++--------
 net/core/ethtool.c |    2 +-
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 0b88eba..105e082 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1353,14 +1353,18 @@ EXPORT_SYMBOL(dev_close);
  */
 void dev_disable_lro(struct net_device *dev)
 {
-	if (dev->ethtool_ops && dev->ethtool_ops->get_flags &&
-	    dev->ethtool_ops->set_flags) {
-		u32 flags = dev->ethtool_ops->get_flags(dev);
-		if (flags & ETH_FLAG_LRO) {
-			flags &= ~ETH_FLAG_LRO;
-			dev->ethtool_ops->set_flags(dev, flags);
-		}
-	}
+	extern int __ethtool_set_flags(struct net_device *, u32);
+	u32 flags;
+
+	if (dev->ethtool_ops && dev->ethtool_ops->get_flags)
+		flags = dev->ethtool_ops->get_flags(dev);
+	else
+		flags = ethtool_op_get_flags(dev);
+
+	if (!(flags & ETH_FLAG_LRO))
+		return;
+
+	__ethtool_set_flags(dev, flags & ~ETH_FLAG_LRO);
 	WARN_ON(dev->features & NETIF_F_LRO);
 }
 EXPORT_SYMBOL(dev_disable_lro);
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index c1a71bb..7371177 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -513,7 +513,7 @@ static int ethtool_set_one_feature(struct net_device *dev,
 	}
 }
 
-static int __ethtool_set_flags(struct net_device *dev, u32 data)
+int __ethtool_set_flags(struct net_device *dev, u32 data)
 {
 	u32 changed;
 
-- 
1.7.2.3

Re: [PATCH] net: implement dev_disable_lro() hw_features compatibility

[Ben Hutchings]

On Fri, 2011-03-18 at 18:42 +0100, Michał Mirosław wrote:
> Implement compatibility with new hw_features for dev_disable_lro().

Good point, but...

> This is a transition path - dev_disable_lro() should be later
> integrated into netdev_fix_features() after all drivers are converted.
>
> There's no point in exporting __ethtool_set_flags() as it and dev_disable_lro()
> are always built-in.
> 
> Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
> ---
> 
> Patch is build-tested only, as I don't have any LRO-capable hardware.
> It might be prettier to move dev_disable_lro() to ethtool.c.

It *looks* right.

>  net/core/dev.c     |   20 ++++++++++++--------
>  net/core/ethtool.c |    2 +-
>  2 files changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/net/core/dev.c b/net/core/dev.c
> index 0b88eba..105e082 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -1353,14 +1353,18 @@ EXPORT_SYMBOL(dev_close);
>   */
>  void dev_disable_lro(struct net_device *dev)
>  {
> -	if (dev->ethtool_ops && dev->ethtool_ops->get_flags &&
> -	    dev->ethtool_ops->set_flags) {
> -		u32 flags = dev->ethtool_ops->get_flags(dev);
> -		if (flags & ETH_FLAG_LRO) {
> -			flags &= ~ETH_FLAG_LRO;
> -			dev->ethtool_ops->set_flags(dev, flags);
> -		}
> -	}
> +	extern int __ethtool_set_flags(struct net_device *, u32);
[...]

Local function declarations are a very bad idea, as they are not checked
against the function definition.  Please declare the function in
<linux/ethtool.h>; that does not oblige us to export it.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

Re: [PATCH] net: implement dev_disable_lro() hw_features compatibility

[David Miller]

From: Ben Hutchings <bhutchings@solarflare.com>
Date: Fri, 18 Mar 2011 18:13:06 +0000

> Local function declarations are a very bad idea, as they are not checked
> against the function definition.  Please declare the function in
> <linux/ethtool.h>; that does not oblige us to export it.

Agreed.

[PATCH v2] net: implement dev_disable_lro() hw_features compatibility

[Michał Mirosław]

Implement compatibility with new hw_features for dev_disable_lro().
This is a transition path - dev_disable_lro() should be later
integrated into netdev_fix_features() after all drivers are converted.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
---

Changes from v1:
 - moved __ethtool_set_flags() prototype to ethtool.h

 include/linux/ethtool.h |    3 +++
 net/core/dev.c          |   19 +++++++++++--------
 net/core/ethtool.c      |    2 +-
 3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index aac3e2e..c9bfe2d 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -614,6 +614,9 @@ enum ethtool_sfeatures_retval_bits {
 
 #include <linux/rculist.h>
 
+/* needed by dev_disable_lro() */
+extern int __ethtool_set_flags(struct net_device *dev, u32 flags);
+
 struct ethtool_rx_ntuple_flow_spec_container {
 	struct ethtool_rx_ntuple_flow_spec fs;
 	struct list_head list;
diff --git a/net/core/dev.c b/net/core/dev.c
index 0b88eba..f453370 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1353,14 +1353,17 @@ EXPORT_SYMBOL(dev_close);
  */
 void dev_disable_lro(struct net_device *dev)
 {
-	if (dev->ethtool_ops && dev->ethtool_ops->get_flags &&
-	    dev->ethtool_ops->set_flags) {
-		u32 flags = dev->ethtool_ops->get_flags(dev);
-		if (flags & ETH_FLAG_LRO) {
-			flags &= ~ETH_FLAG_LRO;
-			dev->ethtool_ops->set_flags(dev, flags);
-		}
-	}
+	u32 flags;
+
+	if (dev->ethtool_ops && dev->ethtool_ops->get_flags)
+		flags = dev->ethtool_ops->get_flags(dev);
+	else
+		flags = ethtool_op_get_flags(dev);
+
+	if (!(flags & ETH_FLAG_LRO))
+		return;
+
+	__ethtool_set_flags(dev, flags & ~ETH_FLAG_LRO);
 	WARN_ON(dev->features & NETIF_F_LRO);
 }
 EXPORT_SYMBOL(dev_disable_lro);
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index c1a71bb..7371177 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -513,7 +513,7 @@ static int ethtool_set_one_feature(struct net_device *dev,
 	}
 }
 
-static int __ethtool_set_flags(struct net_device *dev, u32 data)
+int __ethtool_set_flags(struct net_device *dev, u32 data)
 {
 	u32 changed;
 
-- 
1.7.2.3

Re: [PATCH v2] net: implement dev_disable_lro() hw_features compatibility

[David Miller]

From: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Date: Sat, 19 Mar 2011 03:56:34 +0100 (CET)

> Implement compatibility with new hw_features for dev_disable_lro().
> This is a transition path - dev_disable_lro() should be later
> integrated into netdev_fix_features() after all drivers are converted.
> 
> Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>

I'll apply this, thanks.