On Tue, 2018-02-27 at 08:26 +0100, Marek Szyprowski wrote: > Hi > > I've noticed that USBnet/ASIX AX88772B USB driver produces deplock kernel > warning ("inconsistent lock state") on Chromebook2 Peach-PIT board. No > special activity is needed to reproduce this issue, it happens almost > on every boot. ASIX USB ethernet is connected to XHCI USB host controller > on that board. Is it a known issue? Frankly I have no idea where to look > to fix it. The same adapter connected to EHCI ports on other boards based > on the same SoC works fine without any warnings. > > Here are some more information from that board: > # lsusb > Bus 006 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub > Bus 005 Device 002: ID 0b95:772b ASIX Electronics Corp. AX88772B > Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub > Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub > Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub > Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub > Bus 001 Device 002: ID 2232:1056 Silicon Motion > Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub > > # lsusb -t > /: Bus 06.Port 1: Dev 1, Class=root_hub, Driver=xhci-hcd/1p, 5000M > /: Bus 05.Port 1: Dev 1, Class=root_hub, Driver=xhci-hcd/1p, 480M > |__ Port 1: Dev 2, If 0, Class=Vendor Specific Class, Driver=asix, 480M > /: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci-hcd/1p, 5000M > /: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci-hcd/1p, 480M > /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=exynos-ohci/3p, 12M > /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=exynos-ehci/3p, 480M > |__ Port 1: Dev 2, If 0, Class=Video, Driver=, 480M > |__ Port 1: Dev 2, If 1, Class=Video, Driver=, 480M > > > And the log with mentioned warning: > > [ 17.768040] ================================ > [ 17.772239] WARNING: inconsistent lock state > [ 17.776511] 4.16.0-rc3-next-20180227-00007-g876c53a7493c #453 Not tainted > [ 17.783329] -------------------------------- > [ 17.787580] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. > [ 17.793607] swapper/0/0 [HC0[0]:SC1[1]:HE1:SE0] takes: > [ 17.798751] (&syncp->seq#5){?.-.}, at: [<9b22e5f0>] > asix_rx_fixup_internal+0x188/0x288 > [ 17.806790] {IN-HARDIRQ-W} state was registered at: > [ 17.811677] tx_complete+0x100/0x208 > [ 17.815319] __usb_hcd_giveback_urb+0x60/0xf0 > [ 17.819770] xhci_giveback_urb_in_irq+0xa8/0x240 > [ 17.824469] xhci_td_cleanup+0xf4/0x16c > [ 17.828367] xhci_irq+0xe74/0x2240 > [ 17.831827] usb_hcd_irq+0x24/0x38 > [ 17.835343] __handle_irq_event_percpu+0x98/0x510 > [ 17.840111] handle_irq_event_percpu+0x1c/0x58 > [ 17.844623] handle_irq_event+0x38/0x5c > [ 17.848519] handle_fasteoi_irq+0xa4/0x138 > [ 17.852681] generic_handle_irq+0x18/0x28 > [ 17.856760] __handle_domain_irq+0x6c/0xe4 > [ 17.860941] gic_handle_irq+0x54/0xa0 > [ 17.864666] __irq_svc+0x70/0xb0 > [ 17.867964] arch_cpu_idle+0x20/0x3c > [ 17.871578] arch_cpu_idle+0x20/0x3c > [ 17.875190] do_idle+0x144/0x218 > [ 17.878468] cpu_startup_entry+0x18/0x1c > [ 17.882454] start_kernel+0x394/0x400 > [ 17.886177] irq event stamp: 161912 > [ 17.889616] hardirqs last enabled at (161912): [<7bedfacf>] > __netdev_alloc_skb+0xcc/0x140 > [ 17.897893] hardirqs last disabled at (161911): [<d58261d0>] > __netdev_alloc_skb+0x94/0x140 > [ 17.904903] exynos5-hsi2c 12ca0000.i2c: tx timeout > [ 17.906116] softirqs last enabled at (161904): [<387102ff>] > irq_enter+0x78/0x80 > [ 17.906123] softirqs last disabled at (161905): [<cf4c628e>] > irq_exit+0x134/0x158 > [ 17.925722]. > [ 17.925722] other info that might help us debug this: > [ 17.933435] Possible unsafe locking scenario: > [ 17.933435]. > [ 17.940331] CPU0 > [ 17.942488] ---- > [ 17.944894] lock(&syncp->seq#5); > [ 17.948274] <Interrupt> > [ 17.950847] lock(&syncp->seq#5); > [ 17.954386]. > [ 17.954386] *** DEADLOCK *** > [ 17.954386]. > [ 17.962422] no locks held by swapper/0/0. > [ 17.966011]. > [ 17.966011] stack backtrace: > [ 17.971333] CPU: 0 PID: 0 Comm: swapper/0 Not tainted > 4.16.0-rc3-next-20180227-00007-g876c53a7493c #453 > [ 17.980312] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) > [ 17.986380] [<c0111548>] (unwind_backtrace) from [<c010dbd8>] > (show_stack+0x10/0x14) > [ 17.994128] [<c010dbd8>] (show_stack) from [<c09bd418>] > (dump_stack+0x90/0xc8) > [ 18.001339] [<c09bd418>] (dump_stack) from [<c017fdf8>] > (print_usage_bug+0x25c/0x2cc) > [ 18.009161] [<c017fdf8>] (print_usage_bug) from [<c017c14c>] > (mark_lock+0x290/0x698) > [ 18.014952] exynos5-hsi2c 12ca0000.i2c: tx timeout > [ 18.016899] [<c017c14c>] (mark_lock) from [<c017c9a8>] > (__lock_acquire+0x454/0x1850) > [ 18.029449] [<c017c9a8>] (__lock_acquire) from [<c017e6e0>] > (lock_acquire+0xc8/0x2b8) > [ 18.037272] [<c017e6e0>] (lock_acquire) from [<c05be98c>] > (usbnet_skb_return+0x7c/0x1a0) > [ 18.045356] [<c05be98c>] (usbnet_skb_return) from [<c05b185c>] > (asix_rx_fixup_internal+0x188/0x288) > [ 18.054420] [<c05b185c>] (asix_rx_fixup_internal) from [<c05bfe40>] > (usbnet_bh+0xf8/0x2e4) > [ 18.062694] [<c05bfe40>] (usbnet_bh) from [<c012d6b4>] > (tasklet_action+0x8c/0x13c) > [ 18.070259] [<c012d6b4>] (tasklet_action) from [<c0102214>] > (__do_softirq+0xd4/0x6d4) > [ 18.078089] [<c0102214>] (__do_softirq) from [<c012cf34>] > (irq_exit+0x134/0x158) > [ 18.085480] [<c012cf34>] (irq_exit) from [<c018c444>] > (__handle_domain_irq+0x70/0xe4) > [ 18.093314] [<c018c444>] (__handle_domain_irq) from [<c046400c>] > (gic_handle_irq+0x54/0xa0) > [ 18.101670] [<c046400c>] (gic_handle_irq) from [<c01019f0>] > (__irq_svc+0x70/0xb0) > [ 18.109163] Exception stack(0xc0f01eb8 to 0xc0f01f00) > [ 18.114202] 1ea0: 00000001 00000001 > [ 18.122397] 1ec0: 00000000 c0f0ba80 eef3a540 eef3a540 ee8d2700 > c0f088b4 00000402 c09d23e0 > [ 18.124980] exynos5-hsi2c 12ca0000.i2c: tx timeout > [ 18.130611] 1ee0: c0f0ba80 c0f01f4c 00000000 c0f01f08 c017ea54 > c09d92d4 20000013 ffffffff > [ 18.135504] cpu cpu0: _set_opp_voltage: failed to set voltage > (1250000 1250000 1250000 mV): -110 > [ 18.143690] [<c01019f0>] (__irq_svc) from [<c09d92d4>] > (_raw_spin_unlock_irq+0x28/0x5c) > [ 18.152671] cpufreq: __target_index: Failed to change cpu frequency: -110 > [ 18.160683] [<c09d92d4>] (_raw_spin_unlock_irq) from [<c0152684>] > (finish_task_switch+0xb4/0x254) > [ 18.160696] [<c0152684>] (finish_task_switch) from [<c09d23e0>] > (__schedule+0x290/0xb10) > [ 18.160704] [<c09d23e0>] (__schedule) from [<c09d3134>] > (schedule_idle+0x2c/0x78) > [ 18.160711] [<c09d3134>] (schedule_idle) from [<c01703a0>] > (cpu_startup_entry+0x18/0x1c) > [ 18.200726] [<c01703a0>] (cpu_startup_entry) from [<c0e00c74>] > (start_kernel+0x394/0x400) > > Best regards Please try the attached patch, thanks. drivers/net/usb/usbnet.c | 5 +++-- include/linux/u64_stats_sync.h | 22 ++++++++++++++++++++++ 2 files changed, 25 insertions(+), 2 deletions(-) diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 8a22ff67b0268a588428c61c6a6211e3c6c2a02a..7f5bda0ec9e8520e6db327b713152afdb250255f 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -315,6 +315,7 @@ static void __usbnet_status_stop_force(struct usbnet *dev) void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb) { struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64); + unsigned long flags; int status; if (test_bit(EVENT_RX_PAUSED, &dev->flags)) { @@ -326,10 +327,10 @@ void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb) if (skb->protocol == 0) skb->protocol = eth_type_trans (skb, dev->net); - u64_stats_update_begin(&stats64->syncp); + flags = u64_stats_update_begin_irqsave(&stats64->syncp); stats64->rx_packets++; stats64->rx_bytes += skb->len; - u64_stats_update_end(&stats64->syncp); + u64_stats_update_end_irqrestore(&stats64->syncp, flags); netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n", skb->len + sizeof (struct ethhdr), skb->protocol); diff --git a/include/linux/u64_stats_sync.h b/include/linux/u64_stats_sync.h index 5bdbd9f49395f883ca2dc5aa0d7bbde11f379063..07ee0f84a46caa9e2b1c446f96009f63b3b99f50 100644 --- a/include/linux/u64_stats_sync.h +++ b/include/linux/u64_stats_sync.h @@ -90,6 +90,28 @@ static inline void u64_stats_update_end(struct u64_stats_sync *syncp) #endif } +static inline unsigned long +u64_stats_update_begin_irqsave(struct u64_stats_sync *syncp) +{ + unsigned long flags = 0; + +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) + local_irq_save(flags); + write_seqcount_begin(&syncp->seq); +#endif + return flags; +} + +static inline void +u64_stats_update_end_irqrestore(struct u64_stats_sync *syncp, + unsigned long flags) +{ +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) + write_seqcount_end(&syncp->seq); + local_irq_restore(flags); +#endif +} + static inline void u64_stats_update_begin_raw(struct u64_stats_sync *syncp) { #if BITS_PER_LONG==32 && defined(CONFIG_SMP) -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html