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Message-ID: <530adc71b52e774c92c53d235701710dbc9866a9.camel@redhat.com>
Subject: Re: [PATCH net 1/1] net: stmmac: disable Split Header (SPH) for
 Intel platforms
From:   Paolo Abeni <pabeni@redhat.com>
To:     Tan Tee Min <tee.min.tan@linux.intel.com>,
        Kurt Kanzenbach <kurt@linutronix.de>
Cc:     Giuseppe Cavallaro <peppe.cavallaro@st.com>,
        Alexandre Torgue <alexandre.torgue@foss.st.com>,
        Jose Abreu <joabreu@synopsys.com>,
        "David S . Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Michael Sit Wei Hong <michael.wei.hong.sit@intel.com>,
        Xiaoliang Yang <xiaoliang.yang_1@nxp.com>,
        Wong Vee Khee <vee.khee.wong@linux.intel.com>,
        Ling Pei Lee <pei.lee.ling@intel.com>,
        Bhupesh Sharma <bhupesh.sharma@linaro.org>,
        netdev@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        stable@vger.kernel.org, Voon Wei Feng <weifeng.voon@intel.com>,
        Song Yoong Siang <yoong.siang.song@intel.com>,
        Ong@vger.kernel.org, Boon Leong <boon.leong.ong@intel.com>,
        Tan Tee Min <tee.min.tan@intel.com>
Date:   Thu, 28 Apr 2022 09:05:57 +0200
In-Reply-To: <20220428015538.GC26326@linux.intel.com>
References: <20220426074531.4115683-1-tee.min.tan@linux.intel.com>
         <8735i0ndy7.fsf@kurt> <20220428015538.GC26326@linux.intel.com>
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Hello,

On Thu, 2022-04-28 at 09:55 +0800, Tan Tee Min wrote:
> On Tue, Apr 26, 2022 at 03:58:56PM +0200, Kurt Kanzenbach wrote:
> > Hi,
> > 
> > On Tue Apr 26 2022, Tan Tee Min wrote:
> > > Based on DesignWare Ethernet QoS datasheet, we are seeing the limitation
> > > of Split Header (SPH) feature is not supported for Ipv4 fragmented packet.
> > > This SPH limitation will cause ping failure when the packets size exceed
> > > the MTU size. For example, the issue happens once the basic ping packet
> > > size is larger than the configured MTU size and the data is lost inside
> > > the fragmented packet, replaced by zeros/corrupted values, and leads to
> > > ping fail.
> > > 
> > > So, disable the Split Header for Intel platforms.
> > 
> > Does this issue only apply on Intel platforms?
> 
> According to Synopsys IP support, they have confirmed the header-payload
> splitting for IPv4 fragmented packets is not supported for the Synopsys
> Ether IPs.
> 
> Intel platforms are integrating with GMAC EQoS IP which is impacted by the
> limitation above, so we are changing the default SPH setting to disabled
> for Intel Platforms only.
> 
> If anyone can confirm on their platform also having the same issues,
> then we would change the SPH default to disable across the IPs.

Could you please provide a Fixes tag here? 

Thanks!

Paolo