lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Fri, 27 Dec 2019 16:37:53 -0800 (PST) From: David Miller <davem@...emloft.net> To: martin.blumenstingl@...glemail.com Cc: andrew@...n.ch, f.fainelli@...il.com, netdev@...r.kernel.org, linux-amlogic@...ts.infradead.org, linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org Subject: Re: [PATCH v2 1/1] net: stmmac: dwmac-meson8b: Fix the RGMII TX delay on Meson8b/8m2 SoCs From: Martin Blumenstingl <martin.blumenstingl@...glemail.com> Date: Thu, 26 Dec 2019 20:01:01 +0100 > GXBB and newer SoCs use the fixed FCLK_DIV2 (1GHz) clock as input for > the m250_sel clock. Meson8b and Meson8m2 use MPLL2 instead, whose rate > can be adjusted at runtime. > > So far we have been running MPLL2 with ~250MHz (and the internal > m250_div with value 1), which worked enough that we could transfer data > with an TX delay of 4ns. Unfortunately there is high packet loss with > an RGMII PHY when transferring data (receiving data works fine though). > Odroid-C1's u-boot is running with a TX delay of only 2ns as well as > the internal m250_div set to 2 - no lost (TX) packets can be observed > with that setting in u-boot. > > Manual testing has shown that the TX packet loss goes away when using > the following settings in Linux (the vendor kernel uses the same > settings): > - MPLL2 clock set to ~500MHz > - m250_div set to 2 > - TX delay set to 2ns on the MAC side > > Update the m250_div divider settings to only accept dividers greater or > equal 2 to fix the TX delay generated by the MAC. > > iperf3 results before the change: > [ ID] Interval Transfer Bitrate Retr > [ 5] 0.00-10.00 sec 182 MBytes 153 Mbits/sec 514 sender > [ 5] 0.00-10.00 sec 182 MBytes 152 Mbits/sec receiver > > iperf3 results after the change (including an updated TX delay of 2ns): > [ ID] Interval Transfer Bitrate Retr Cwnd > [ 5] 0.00-10.00 sec 927 MBytes 778 Mbits/sec 0 sender > [ 5] 0.00-10.01 sec 927 MBytes 777 Mbits/sec receiver > > Fixes: 4f6a71b84e1afd ("net: stmmac: dwmac-meson8b: fix internal RGMII clock configuration") > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@...glemail.com> Applied and queued up for -stable, thanks.
Powered by blists - more mailing lists