[Intel-wired-lan] [PATCH net-next 1/2] ice: Implement control of FCS/CRC stripping

[Mekala, SunithaX D]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces at osuosl.org> On Behalf Of Maciej Fijalkowski
> Sent: Tuesday, June 28, 2022 3:59 AM
> To: Gerasymenko, Anatolii <anatolii.gerasymenko at intel.com>
> Cc: intel-wired-lan at lists.osuosl.org; Brandeburg, Jesse <jesse.brandeburg at intel.com>
> Subject: Re: [Intel-wired-lan] [PATCH net-next 1/2] ice: Implement control of FCS/CRC stripping
>
> On Tue, Jun 28, 2022 at 12:44:03PM +0200, Anatolii Gerasymenko wrote:
> From: Jesse Brandeburg <jesse.brandeburg at intel.com>
> 
> The driver can allow the user to configure whether the CRC aka the FCS 
> (Frame Check Sequence) is DMA'd to the host as part of the receive 
> buffer.  The driver usually wants this feature disabled so that the 
> hardware checks the FCS and strips it in order to save PCI bandwidth.
> 
> Control the reception of FCS to the host using the command:
> ethtool -K eth0 rx-fcs <on|off>
> 
> The default shown in ethtool -k eth0 | grep fcs; should be "off", as 
> the hardware will drop any frame with a bad checksum, and DMA of the 
> checksum is useless overhead especially for small packets.
> 
> Testing Hints:
> test the FCS/CRC arrives with received packets using tcpdump -nnpi 
> eth0 -xxxx and it should show crc data as the last 4 bytes of the 
> packet. Can also use wireshark to turn on CRC checking and check the 
> data is correct.
> 
> Signed-off-by: Jesse Brandeburg <jesse.brandeburg at intel.com>
> Co-Developed-by: Anatolii Gerasymenko <anatolii.gerasymenko at intel.com>
> Signed-off-by: Anatolii Gerasymenko <anatolii.gerasymenko at intel.com>
> Acked-by: Jesse Brandeburg <jesse.brandeburg at intel.com>

> Sorry but NACK.
>
> Could you pick
> https://lore.kernel.org/bpf/20220616180609.905015-2-maciej.fijalkowski@intel.com/
>
> and base your code on top of that? I have specially pulled out the switch the 'changed' netdev features out of my loopback code so that we both can take a favor of it.
>
> Looks like you're going to be the first with landing the crc strip to the netdev as I'm lost in fixing some stuff in libbpf/af_xdp :p
>
> TBH the loopback toggle would also fit to your series:
> https://lore.kernel.org/bpf/20220616180609.905015-3-maciej.fijalkowski@intel.com/
>
> Thanks!
>
> ---
>  drivers/net/ethernet/intel/ice/ice.h         |  1 +
>  drivers/net/ethernet/intel/ice/ice_base.c    |  2 +-
>  drivers/net/ethernet/intel/ice/ice_ethtool.c |  5 +-
>  drivers/net/ethernet/intel/ice/ice_lib.c     | 21 +++++++++
>  drivers/net/ethernet/intel/ice/ice_lib.h     |  2 +
>  drivers/net/ethernet/intel/ice/ice_main.c    | 48 ++++++++++++++++++--
>  drivers/net/ethernet/intel/ice/ice_txrx.h    |  3 +-
>  7 files changed, 71 insertions(+), 11 deletions(-)
>
Tested-by: Sunitha Mekala <sunithax.d.mekala at intel.com> (A Contingent worker at Intel)