From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Date: Tue, 29 Jan 2019 18:20:15 +0000 Subject: Re: [PATCH 4/7] sh_eth: offload RX checksum on R8A7740 Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Sergei Shtylyov Cc: netdev , "David S. Miller" , Linux-Renesas , Linux-sh list Hi Sergei, On Sun, Jan 27, 2019 at 6:41 PM Sergei Shtylyov wrote: > The R-Mobile A1 (R8A7740) SoC manual describes the Ether MAC's RX checksum > offload the same way as it's implemented in the EtherAVB MAC... > > Signed-off-by: Sergei Shtylyov Thanks for your patch! Running netperf as described in patch 2/7, perf tells me there's a reduction for csum_partial from ca. 1.9% to 0.01%, so this feature seems to work. Hence: Tested-by: Geert Uytterhoeven However, while effective according to perf results, using ethtool to enable/disable the feature prints an error message: root@armadillo:~# ethtool -K eth0 rx on Cannot get device udp-fragmentation-offload settings: Operation not supported Cannot get device udp-fragmentation-offload settings: Operation not supported root@armadillo:~# ethtool -K eth0 rx off Cannot get device udp-fragmentation-offload settings: Operation not supported Cannot get device udp-fragmentation-offload settings: Operation not supported root@armadillo:~# Do you have any clue? Does this needs testing on R-Mobile A1 with VLAN enabled, too, or is that independent from the underlying sh-eth hardware version? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds