From: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>
To: "Topel, Bjorn" <bjorn.topel@intel.com>,
"dev@dpdk.org" <dev@dpdk.org>,
"Zhang, Helin" <helin.zhang@intel.com>
Cc: "Xu, Qian Q" <qian.q.xu@intel.com>,
"Yao, Lei A" <lei.a.yao@intel.com>,
"Wu, Jingjing" <jingjing.wu@intel.com>,
"thomas.monjalon@6wind.com" <thomas.monjalon@6wind.com>
Subject: Re: [dpdk-dev] [PATCH] examples/l3fwd: force CRC stripping for i40evf
Date: Wed, 9 Nov 2016 12:13:45 +0000 [thread overview]
Message-ID: <2601191342CEEE43887BDE71AB9772583F0D3022@irsmsx105.ger.corp.intel.com> (raw)
In-Reply-To: <b2592ded-badc-5445-526c-d0203b48f592@intel.com>
> -----Original Message-----
> From: Topel, Bjorn
> Sent: Wednesday, November 9, 2016 11:28 AM
> To: Ananyev, Konstantin <konstantin.ananyev@intel.com>; dev@dpdk.org; Zhang, Helin <helin.zhang@intel.com>
> Cc: Xu, Qian Q <qian.q.xu@intel.com>; Yao, Lei A <lei.a.yao@intel.com>; Wu, Jingjing <jingjing.wu@intel.com>;
> thomas.monjalon@6wind.com
> Subject: Re: [dpdk-dev] [PATCH] examples/l3fwd: force CRC stripping for i40evf
>
> >> Correct, so the broader question would be "what is the correct
> >> behavior for an example application, when a port configuration
> >> isn't supported by the hardware?".
> >>
> >> My stand, FWIW, is that igb and ixgbe should have the same
> >> semantics as i40e currently has, i.e. return an error to the user
> >> if the port is mis-configured, NOT changing the setting behind the
> >> users back.
> >>
> >
> > Fine by me, but then it means that the fix haw to include changes
> > for all apps plus ixgbe and igb PMDs, correct? :)
>
> Ugh. Correct, I guess. :-)
>
> As for ixgbe and igb - they need a patch changing from silent ignore to
> explicit error. Regarding the apps, I guess all the apps that rely on
> that disabling CRC stripping always work, need some work. Or should all
> the example applications have CRC stripping *enabled* by default? I'd
> assume that all DPDK supported NICs has support for CRC stripping
From the sources, it seems that only nfp doesn't support HW CRC stripping.
In fact, as I can see some non-Intel PMDs just ignore hw_stip_crc value
and assume that CRC strip is always on.
> and I
> guess this is the rational for having it on by default for Intel VFs.
>
> In general, for the example applications, if an application relies on a
> property for a port, that the hardware doesn't support -- what would be
> the desired behavior? Or is it implied that the example applications
> only use a common, minimal set of features that are know to be supported
> by all DPDK supported hardware?
>
> Isn't it perfectly valid that some example applications wont run for all
> hardware?
>
> Finally, why doesn't l3fwd have the CRC stripped?
I don’t know any good reason for that for l3fwd or any other sample app.
I think it is just a 'historical' reason.
Konstantin
>
>
> Björn
next prev parent reply other threads:[~2016-11-09 12:13 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-09 8:23 Björn Töpel
2016-11-09 8:37 ` Yao, Lei A
2016-11-09 9:28 ` Thomas Monjalon
2016-11-09 9:39 ` Björn Töpel
2016-11-09 9:46 ` Ananyev, Konstantin
2016-11-09 10:05 ` Björn Töpel
2016-11-09 10:22 ` Thomas Monjalon
2016-11-09 11:08 ` Ananyev, Konstantin
2016-11-09 11:27 ` Björn Töpel
2016-11-09 12:13 ` Ananyev, Konstantin [this message]
2016-11-09 13:01 ` Zhang, Helin
2016-11-09 13:09 ` Björn Töpel
2016-11-10 5:49 ` Yao, Lei A
2016-11-10 6:17 ` Björn Töpel
2016-11-10 7:55 ` Thomas Monjalon
2016-11-10 7:59 ` Björn Töpel
2016-11-10 13:50 Mori, Naoyuki
2016-11-10 14:32 ` Thomas Monjalon
2016-11-10 14:43 ` Mori, Naoyuki
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