Re: [PATCH] net: ethernet: use ip_hdrlen() instead of bit shift

From: Simon Horman
Date: Fri Aug 02 2024 - 10:40:38 EST


On Fri, Aug 02, 2024 at 03:15:34PM +0100, Simon Horman wrote:
> On Fri, Aug 02, 2024 at 02:44:21PM +0900, Moon Yeounsu wrote:
> > `ip_hdr(skb)->ihl << 2` are the same as `ip_hdrlen(skb)`
> > Therefore, we should use a well-defined function not a bit shift
> > to find the header length.
> >
> > It also compress two lines at a single line.
> >
> > Signed-off-by: Moon Yeounsu <yyyynoom@xxxxxxxxx>
>
> Firstly, I think this clean-up is both correct and safe. Safe because
> ip_hdrlen() only relies on ip_hdr(), which is already used in the same code
> path. And correct because ip_hdrlen multiplies ihl by 4, which is clearly
> equivalent to a left shift of 2 bits.
>
> However, I do wonder about the value of clean-ups for what appears to be a
> very old driver, which hasn't received a new feature for quite sometime
>
> And further, I wonder if we should update this driver from "Maintained" to
> "Odd Fixes" as the maintainer, "Guo-Fu Tseng" <cooldavid@xxxxxxxxxxxxx>,
> doesn't seem to have been seen by lore since early 2020.
>
> https://lore.kernel.org/netdev/20200219034801.M31679@xxxxxxxxxxxxx/

By "Odd Fixes" I meant "Orphan"

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