Re: [PATCH v3 1/4] net: Add support for hardware-offloaded encapsulation

[David Miller <davem@davemloft.net>]

From: Joseph Gasparakis <joseph.gasparakis@intel.com>
Date: Fri, 7 Dec 2012 11:41:46 -0800 (PST)

> 
> 
> On Fri, 7 Dec 2012, David Miller wrote:
> 
>> From: Joseph Gasparakis <joseph.gasparakis@intel.com>
>> Date: Fri, 7 Dec 2012 10:24:17 -0800 (PST)
>> 
>> > So the idea here is that the driver will use the headers for checksumming 
>> > if the skb->encapsulation bit is on. The bit should be set in the protocol 
>> > driver.
>> > 
>> > To answer the second comment, the flags that we use in this series of 
>> > patches is NETIF_F_IP_CSUM, NETIF_F_IPV6_CSUM and NETIF_F_SG. These are 
>> > the bits that we propose will be used for checksumming of encapsulation. 
>> > As per a previous comment in v2, the hw_enc_features field should be used 
>> > also in the future when NICs have more encap offloads, so one could
>> > indicate these features there from the driver.
>> > 
>> > Furthermore, I submitted a patch for Rx checksumming, where NETIF_F_RXCSUM 
>> > is used, again in conjunction with skb->encapsulation flag. As I mention 
>> > in my logs, the driver is expected to set the ip_summed to UNNECESSARY and 
>> > turn the skb->encapsulation on, to indicate that the inner headers are 
>> > already HW checksummed.
>> > 
>> 
>> This is the kind of language that belongs in the commit message and
>> code comments.
>> 
> Sure. I'll wait to gather some more feedback if there is any and I will 
> re-spin this off adding more code comments and clarify this in the logs.

Great.

Please note that this request applies to your receive side change too.