On 31.05.2019 16:14, Andrew Lunn wrote: > On Fri, May 31, 2019 at 03:19:20PM +0200, Paul Menzel wrote: >> Dear Linux folks, >> >> >> On several systems with different network devices and drivers (e1000e, >> r8169, tg3) >> it looks like getting the link up takes over three seconds. >> >> ### e1000e ### >> >> [ 1.999678] e1000e: Intel(R) PRO/1000 Network Driver - 3.2.6-k >> [ 2.000374] e1000e: Copyright(c) 1999 - 2015 Intel Corporation. >> [ 2.001206] e1000e 0000:00:1f.6: Interrupt Throttling Rate (ints/sec) set >> to dynamic conservative mode >> [ 2.412096] e1000e 0000:00:1f.6 0000:00:1f.6 (uninitialized): registered >> PHC clock >> [ 2.495295] e1000e 0000:00:1f.6 eth0: (PCI Express:2.5GT/s:Width x1) >> 64:00:6a:2c:10:c1 >> [ 2.496204] e1000e 0000:00:1f.6 eth0: Intel(R) PRO/1000 Network Connection >> [ 2.497024] e1000e 0000:00:1f.6 eth0: MAC: 12, PHY: 12, PBA No: FFFFFF-0FF >> [ 15.614031] e1000e 0000:00:1f.6 net00: renamed from eth0 >> [ 18.679325] e1000e: net00 NIC Link is Up 1000 Mbps Full Duplex, Flow >> Control: None > > Hi Paul > > All the Intel drivers do there own PHY handling, so i cannot speak for them. > >> >> ### r8169 ### >> >> [ 33.433103] r8169 0000:18:00.0: enabling device (0000 -> 0003) >> [ 33.453834] libphy: r8169: probed >> [ 33.456629] r8169 0000:18:00.0 eth0: RTL8168h/8111h, 30:9c:23:04:d6:98, >> XID 541, IRQ 52 >> [ 33.456631] r8169 0000:18:00.0 eth0: jumbo features [frames: 9200 bytes, >> tx checksumming: ko] >> [ 33.607384] r8169 0000:18:00.0 enp24s0: renamed from eth0 >> [ 34.134035] Generic Realtek PHY r8169-1800:00: attached PHY driver >> [Generic Realtek PHY] (mii_bus:phy_addr=r8169-1800:00, irq=IGNORE) >> [ 34.215244] r8169 0000:18:00.0 enp24s0: Link is Down >> [ 37.822536] r8169 0000:18:00.0 enp24s0: Link is Up - 1Gbps/Full - flow >> control rx/tx > > This is using the generic PHY framework and drivers. > > You can see here irq=IGNORE. This implies interrupts are not being > used. So it will poll the PHY once per second. If you can get > interrupts working, you can save 1/2 second on average. > irq=IGNORE means the MAC interrupt is used (using phy_mac_interrupt).
> >> ### tg3 ### >> >> [ 2.015604] tg3.c:v3.137 (May 11, 2014) >> [ 2.025613] tg3 0000:04:00.0 eth0: Tigon3 [partno(BCM95762) rev 5762100] >> (PCI Express) MAC address 54:bf:64:70:a5:f9 >> [ 2.026955] tg3 0000:04:00.0 eth0: attached PHY is 5762C >> (10/100/1000Base-T Ethernet) (WireSpeed[1], EEE[1]) >> [ 2.028252] tg3 0000:04:00.0 eth0: RXcsums[1] LinkChgREG[0] MIirq[0] >> ASF[1] TSOcap[1] >> [ 2.029462] tg3 0000:04:00.0 eth0: dma_rwctrl[00000001] dma_mask[64-bit] >> [ 6.376904] tg3 0000:04:00.0 net00: renamed from eth0 >> [ 10.240411] tg3 0000:04:00.0 net00: Link is up at 1000 Mbps, full duplex >> [ 10.240412] tg3 0000:04:00.0 net00: Flow control is on for TX and on for >> RX >> [ 10.240413] tg3 0000:04:00.0 net00: EEE is disabled >> > > Another MAC driver which does not use the generic framework. > >> If the time cannot be decreased, are there alternative strategies to get a >> link >> up as fast as possible? For fast boot systems, it’d be interesting if first >> a slower speed could be negotiated and later it would be changed. > The following presentation should help to understand which factors contribute to the >3s for auto-negotiation. http://www.ieee802.org/3/af/public/jan02/brown_1_0102.pdf > You can use ethtool to set the modes it will offer for auto-neg. So > you could offer 10/half and see if that comes up faster. > > ethtool -s eth0 advertise 0x001 > > But you are still going to have to wait the longer time when you > decide it is time to swap to the full bandwidth. > > Andrew > Heiner
