Messages in this thread | | | From | Joel Stanley <> | Date | Tue, 17 May 2022 09:20:41 +0000 | Subject | Re: [PATCH net v2] net: ftgmac100: Disable hardware checksum on AST2600 |
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On Fri, 13 May 2022 at 01:46, Dylan Hung <dylan_hung@aspeedtech.com> wrote: > > > -----Original Message----- > > From: joel.stan@gmail.com [mailto:joel.stan@gmail.com] On Behalf Of Joel > > Stanley > > Sent: Friday, May 13, 2022 7:20 AM > > To: David S . Miller <davem@davemloft.net>; Jakub Kicinski > > <kuba@kernel.org>; Paolo Abeni <pabeni@redhat.com>; Benjamin > > Herrenschmidt <benh@kernel.crashing.org>; Dylan Hung > > <dylan_hung@aspeedtech.com>; David Wilder <dwilder@us.ibm.com> > > Cc: openbmc@lists.ozlabs.org; netdev@vger.kernel.org; > > linux-kernel@vger.kernel.org; David Wilder <wilder@us.ibm.com> > > Subject: [PATCH net v2] net: ftgmac100: Disable hardware checksum on > > AST2600 > > > > The AST2600 when using the i210 NIC over NC-SI has been observed to > > produce incorrect checksum results with specific MTU values. This was first > > observed when sending data across a long distance set of networks. > > > > On a local network, the following test was performed using a 1MB file of > > random data. > > > > On the receiver run this script: > > > > #!/bin/bash > > while [ 1 ]; do > > # Zero the stats > > nstat -r > /dev/null > > nc -l 9899 > test-file > > # Check for checksum errors > > TcpInCsumErrors=$(nstat | grep TcpInCsumErrors) > > if [ -z "$TcpInCsumErrors" ]; then > > echo No TcpInCsumErrors > > else > > echo TcpInCsumErrors = $TcpInCsumErrors > > fi > > done > > > > On an AST2600 system: > > > > # nc <IP of receiver host> 9899 < test-file > > > > The test was repeated with various MTU values: > > > > # ip link set mtu 1410 dev eth0 > > > > The observed results: > > > > 1500 - good > > 1434 - bad > > 1400 - good > > 1410 - bad > > 1420 - good > > > > The test was repeated after disabling tx checksumming: > > > > # ethtool -K eth0 tx-checksumming off > > > > And all MTU values tested resulted in transfers without error. > > > > An issue with the driver cannot be ruled out, however there has been no bug > > discovered so far. > > > > David has done the work to take the original bug report of slow data transfer > > between long distance connections and triaged it down to this test case. > > > > The vendor suspects this this is a hardware issue when using NC-SI. The fixes > > line refers to the patch that introduced AST2600 support. > > > > Fixes: 39bfab8844a0 ("net: ftgmac100: Add support for DT phy-handle > > property") > > Reported-by: David Wilder <wilder@us.ibm.com> > > Signed-off-by: Joel Stanley <joel@jms.id.au>
> Reviewed-by: Dylan Hung <dylan_hung@aspeedtech.com>
Thank you Dylan. I've added your r-b to v3, as the only changes are to the wrapping of the commit message.
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