My device: roc-rk3328-cc It's a SBC(Single Board Computer) use soc Rockchip RK3328 How to reproduce this bug: just running a mainline linux kernel,then run iperf3 to test. I also tried this patch https://patchwork.kernel.org/patch/10178969/ ,It slightly improved but cannot completely solve this problem. dmesg summary: [14755.405897] ------------[ cut here ]------------ [14755.406386] NETDEV WATCHDOG: eth0 (rk_gmac-dwmac): transmit queue 0 timed out [14755.407258] WARNING: CPU: 2 PID: 0 at net/sched/sch_generic.c:473 dev_watchdog+0x2ac/0x2b8 [14755.407992] Modules linked in: 8021q garp mrp stp llc rockchipdrm analogix_dp phy_rockchip_inno_hdmi tcp_bbr sch_fq [14755.408985] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.17.0-rc7-1-90343-g15e473367050-dirty #1 [14755.409762] Hardware name: Firefly roc-rk3328-cc (DT) [14755.410224] pstate: 20000005 (nzCv daif -PAN -UAO) [14755.410664] pc : dev_watchdog+0x2ac/0x2b8 [14755.411034] lr : dev_watchdog+0x2ac/0x2b8 [14755.411396] sp : ffff000008013d80 [14755.411696] x29: ffff000008013d80 x28: 0000000000000005 [14755.412184] x27: 0000000000000101 x26: 00000000ffffffff [14755.412670] x25: ffff800079d604b8 x24: 0000000000000002 [14755.413156] x23: ffff800079d6049c x22: ffff80007b74de80 [14755.413641] x21: ffff000009b07000 x20: ffff800079d60000 [14755.414128] x19: 0000000000000000 x18: 0000000000000010 [14755.414614] x17: 0000000000000000 x16: ffff000008229758 [14755.415099] x15: ffffffffffffffff x14: ffff000009b09d88 [14755.415585] x13: ffff000089cb16f7 x12: ffff000009cb16ff [14755.416073] x11: ffff000009b23000 x10: ffff000008013a60 [14755.416557] x9 : 00000000ffffffd0 x8 : ffff00000874ee68 [14755.417044] x7 : 756575712074696d x6 : 000000000000017e [14755.417525] x5 : ffff0000085b5400 x4 : 0000000000000004 [14755.418012] x3 : ffff000009b0c850 x2 : ffff80007c3d3800 [14755.418496] x1 : bea2cbb4ea219900 x0 : 0000000000000000 [14755.418988] Call trace: [14755.419226] dev_watchdog+0x2ac/0x2b8 [14755.419574] call_timer_fn+0x20/0x78 [14755.419903] expire_timers+0xa8/0xb8 [14755.420239] run_timer_softirq+0xa4/0x190 [14755.420610] __do_softirq+0x124/0x220 [14755.420951] irq_exit+0xb0/0xd0 [14755.421250] __handle_domain_irq+0x64/0xb8 [14755.421627] gic_handle_irq+0x50/0xa0 [14755.421967] el1_irq+0xb0/0x128 [14755.422265] arch_cpu_idle+0x10/0x18 [14755.422600] do_idle+0x208/0x270 [14755.422896] cpu_startup_entry+0x20/0x28 [14755.423265] secondary_start_kernel+0x14c/0x160 [14755.423675] ---[ end trace 633d025b2aafb3cb ]--- [14755.424181] rk_gmac-dwmac ff540000.ethernet eth0: Reset adapter. [14755.427911] RTL8211E Gigabit Ethernet stmmac-0:00: attached PHY driver [RTL8211E Gigabit Ethernet] (mii_bus:phy_addr=stmmac-0:00, irq=POLL) [14755.441983] rk_gmac-dwmac ff540000.ethernet eth0: PTP not supported by HW [14755.442989] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready [14759.535770] rk_gmac-dwmac ff540000.ethernet eth0: Link is Up - 1Gbps/Full - flow control rx/tx [14759.536606] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
$ iperf3 -M 1480 -f k -c 192.168.31.7 -t 20 --logfile iperf3.log $ cat iperf3.log Connecting to host 192.168.31.7, port 5201 [ 6] local 192.168.31.88 port 44316 connected to 192.168.31.7 port 5201 [ ID] Interval Transfer Bitrate Retr Cwnd [ 6] 0.00-1.00 sec 42.1 MBytes 353366 Kbits/sec 42 1.43 KBytes [ 6] 1.00-2.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 2.00-3.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 3.00-4.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 4.00-5.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 5.00-6.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 6.00-7.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 7.00-8.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 8.00-9.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 9.00-10.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 10.00-11.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 11.00-12.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 12.00-13.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 13.00-14.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 14.00-15.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 15.00-16.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 16.00-17.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 17.00-18.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 18.00-19.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes [ 6] 19.00-20.00 sec 0.00 Bytes 0.00 Kbits/sec 0 1.43 KBytes - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate Retr [ 6] 0.00-20.00 sec 42.1 MBytes 17675 Kbits/sec 42 sender [ 6] 0.00-20.00 sec 40.6 MBytes 17007 Kbits/sec receiver iperf Done.