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

From: Joseph Gasparakis
Date: Fri Dec 07 2012 - 14:33:14 EST

On Fri, 7 Dec 2012, David Miller wrote:

> From: Joseph Gasparakis <joseph.gasparakis@xxxxxxxxx>
> 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.

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