Hi, On Fri, Aug 17, 2018 at 9:32 AM Jerome Brunet <jbru...@baylibre.com> wrote: > > On Fri, 2018-05-18 at 14:55 +0100, Jose Abreu wrote: > > This is cutting down performance. Once the timer is armed it should run > > after the time expires for the first packet sent and not the last one. > > > > After this change, running iperf, the performance gain is +/- 24%. > > Hi Guys, > > Since v4.18, we are getting a serious regression on Amlogic based SoCs. > I have tested this on amlogic's: > * gxbb S905 p200 (Micrel KSZ9031 - 1GBps) > * axg A113 s400 (Realtek RTL8211F - 1GBps) > > Both SoCs use the synopsys gmac with stmmac driver. I can confirm this on Odroid-C1 (Meson8b SoC with RTL8211F RGMII PHY) as well
> I first noticed that running NFS root filesystem became unstable but I could > not > understand why. Then, running a download as simple test with iperf3 (from an > initramfs) will break the 'network' in matter of seconds. I didn't run iperf, simply downloading the latest rootfs package updates (on Arch Linux ARM) caused the network to break > I don't know exactly what breaks but bisect clearly assign the blame to this > change. Reverting the change solve this problem. > > I'll be happy to make more tests to help understand what is happening here. if some latency is fine then I can also help testing here's a bootlog excerpt with the info from the dwmac-meson8b driver (used on all platforms listed above): meson8b-dwmac c9410000.ethernet: PTP uses main clock meson8b-dwmac c9410000.ethernet: User ID: 0x10, Synopsys ID: 0x37 meson8b-dwmac c9410000.ethernet: DWMAC1000 meson8b-dwmac c9410000.ethernet: DMA HW capability register supported meson8b-dwmac c9410000.ethernet: RX Checksum Offload Engine supported meson8b-dwmac c9410000.ethernet: COE Type 2 meson8b-dwmac c9410000.ethernet: TX Checksum insertion supported meson8b-dwmac c9410000.ethernet: Wake-Up On Lan supported meson8b-dwmac c9410000.ethernet: Normal descriptors meson8b-dwmac c9410000.ethernet: Ring mode enabled meson8b-dwmac c9410000.ethernet: Enable RX Mitigation via HW Watchdog Timer ... meson8b-dwmac c9410000.ethernet eth0: device MAC address [...random mac address...] RTL8211F Gigabit Ethernet stmmac-0:00: attached PHY driver [RTL8211F Gigabit Ethernet] (mii_bus:phy_addr=stmmac-0:00, irq=27) ... meson8b-dwmac c9410000.ethernet eth0: No Safety Features support found meson8b-dwmac c9410000.ethernet eth0: PTP not supported by HW IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready Regards Martin