Re: [PATCH net-next v2 0/2] Add HW checksum offload support for RZ/G2L GbEthernet IP

[Sergey Shtylyov <s.shtylyov@omp.ru>]

Hello!

On 1/24/24 1:21 PM, Biju Das wrote:

> This patch series aims to add HW checksum offload supported by TOE module
> found on the RZ/G2L Gb ethernet IP.

   Your previous try was back in 2021, still the cover letter has the same
issues (hm, I didn't point out those back then).

> The TOE has hw support for calculating IP header and TCP/UDP/ICMP checksum
> for both IPV4 and IPV6.
> 
> For Rx, the result of checksum calculation is attached to last 4byte
> of ethernet frames.

   "For Rx, the 4-byte result of checksum calculation is attached to the
Ethernet frames", you wanted to say?

> First 2bytes is result of IPV4 header checksum
> and next 2 bytes is TCP/UDP/ICMP.

   TCP/UDP/ICMP checksum, you mean?

> If frame does not have error "0000" attached to checksum calculation

   "If a frame does not have error, 0x0000 is attached as a checksum
calculation result", you wanted to say?

> result. For unsupported frames "ffff" is attached to checksum calculation

   s/to/as/, again?

> result. Cases like IPV6, IPV4 header is always set to "FFFF".

   In case of an IPv6 packet, IPv4 checksum is always set to 0xFFFF",
you wanted to say?

> For Tx, the result of checksum calculation is set to the checksum field of
> each IPv4 Header/TCP/UDP/ICMP of ethernet frames. For the unsupported
> frames, those fields are not changed. If a transmission frame is an UDP
> frame of IPv4 and its checksum value in the UDP header field is H’0000,

   I think you can call it just UDPv4...

> TOE does not calculate checksum for UDP part of this frame as it is
> optional function as per standards.
> 
> Add Tx/Rx checksum offload supported by TOE for IPV4 and TCP/UDP protocols.
> 
> Results of iperf3 in Mbps
> 
> RZ/V2L:
> TCP(Tx/Rx) results with checksum offload Enabled:	{921,932}
> TCP(Tx/Rx) results with checksum offload Disabled:	{867,612}
> 
> UDP(Tx/Rx) results with checksum offload Enabled:	{950,946}
> UDP(Tx/Rx) results with checksum offload Disabled:	{952,920}
> 
> RZ/G2L:
> TCP(Tx/Rx) results with checksum offload Enabled:	{920,936}
> TCP(Tx/Rx) results with checksum offload Disabled:	{871,626}
> 
> UDP(Tx/Rx) results with checksum offload Enabled:	{953,950}
> UDP(Tx/Rx) results with checksum offload Disabled:	{954,920}
> 
> RZ/G2LC:
> TCP(Tx/Rx) results with checksum offload Enabled:	{927,936}
> TCP(Tx/Rx) results with checksum offload Disabled:	{889,626}
> 
> UDP(Tx/Rx) results with checksum offload Enabled:	{950,946}
> UDP(Tx/Rx) results with checksum offload Disabled:	{949,944}

   Too many figures, I think... :-)
   How RZ/G2L SoC is different from RZ/G2LC?

> v1->v2:
>  * Updated covering letter and results
>  * Fixed the sparse warnings for patch#1 by replacing __sum16->__wsum.
> 
> Note:
>  This patches are tested with [1] without the CPU performance is not good

   Without CPU? I guess the performance would be 0. Seriously, this is
hardly parseable... :-)
 
>  [1] https://lore.kernel.org/all/20240117190545.596057-1-vincent.guittot@linaro.org/
> 
> Biju Das (2):
>   ravb: Add Rx checksum offload support
>   ravb: Add Tx checksum offload support

   These summaries sound like you're adding checksum offload support for
all supported SoCs while you only do that for those having GbEther...

[...]

MBR, Sergey