Re: [PATCH v2] net/tap: add CRC stripping capability

[Thomas Monjalon <thomas@monjalon.net>]

15/02/2018 22:55, Stephen Hemminger:
> On Tue, 13 Feb 2018 17:35:20 +0100
> Thomas Monjalon <thomas@monjalon.net> wrote:
> 
> > 13/02/2018 09:14, Ophir Munk:
> > > CRC stripping is executed in the kernel outside of TAP PMD scope.
> > > There is no prevention that the TAP PMD will report on Rx CRC
> > > stripping capability.
> > > In the corrupted code, TAP PMD did not report on this capability.
> > > The fix enables TAP PMD to report that Rx CRC stripping is supported.
> > > 
> > > Fixes: 02f96a0a82d1 ("net/tap: add TUN/TAP device PMD")
> > > Cc: stable@dpdk.org
> > > 
> > > Signed-off-by: Ophir Munk <ophirmu@mellanox.com>  
> > 
> > Applied, thanks
> > 
> 
> The whole CRC strip flag notion is backwards. It really should of been
> a bit set if driver allows preserving CRC.
> 
> Since changing the ABI is not possible right now;
> the ethdev core ought to log a warning whenever driver is registered
> without CRC_STRIP flag.
> 
> Or is lack of CRC_STRIP in offload flags implying that driver can
> do strip and not stripping?

I agree we should change the API.
Let's open a new thread to discuss it with a wider audience.