Re: [PATCH net v4 0/3] Fix large frames in the Gemini ethernet driver

[Vladimir Oltean]

On Thu, Nov 09, 2023 at 10:03:11AM +0100, Linus Walleij wrote:
> This is the result of a bug hunt for a problem with the
> RTL8366RB DSA switch leading me wrong all over the place.
> 
> I am indebted to Vladimir Oltean who as usual pointed
> out where the real problem was, many thanks!
> 
> Tryig to actually use big ("jumbo") frames on this
> hardware uncovered the real bugs. Then I tested it on
> the DSA switch and it indeed fixes the issue.
> 
> To make sure it also works fine with big frames on
> non-DSA devices I also copied a large video file over
> scp to a device with maximum frame size, the data
> was transported in large TCP packets ending up in
> 0x7ff sized frames using software checksumming at
> ~2.0 MB/s.
> 
> If I set down the MTU to the standard 1500 bytes so
> that hardware checksumming is used, the scp transfer
> of the same file was slightly lower, ~1.8-1.9 MB/s.
> 
> Despite this not being the best test it shows that
> we can now stress the hardware with large frames
> and that software checksum works fine.
> 
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> ---

Thanks for being persistent with this! I hope we didn't miss today's
"net" pull request :)