From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20696C43215 for ; Tue, 3 Dec 2019 09:58:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E3103206DF for ; Tue, 3 Dec 2019 09:58:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=endian-se.20150623.gappssmtp.com header.i=@endian-se.20150623.gappssmtp.com header.b="fN6VeGur" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726131AbfLCJ6j (ORCPT ); Tue, 3 Dec 2019 04:58:39 -0500 Received: from mail-io1-f67.google.com ([209.85.166.67]:46032 "EHLO mail-io1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726086AbfLCJ6i (ORCPT ); Tue, 3 Dec 2019 04:58:38 -0500 Received: by mail-io1-f67.google.com with SMTP id i11so2938212ioi.12 for ; Tue, 03 Dec 2019 01:58:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=endian-se.20150623.gappssmtp.com; s=20150623; h=mime-version:from:date:message-id:subject:cc; bh=W1tmd826wzxxw2dz8JHNgNRaQybNm4AACGIANRlyga0=; b=fN6VeGurros2MpqJOXm5H5Zwx7Kpp5X3QvQ8B3RXJocdG59tgYiAvxuyOy46C3d17a 4QwpWBBiQDy90L/tXwGkzwhFDSnvGqgSRvepxZUkgad7A7gwXQai/XFSk5upT4W9Vk2y ND990M8EPQ89bt8W7kOMHArEnQP1QB5fQRNBq/dmTs67AvfiT9fKqvt8etR5IdREWn1J Eto3Qh8jr/8HTApEZgwC1ZVyvP5UI34vPKKvnTIMg3SiB5qQ4YWiRrn161/FkFgtQC41 ZDltmcoHMBhBo5Rfs62vyrq0n/bYqgj/JJCEXKNfJrsakVTq7I8lLtVTZRFyD5PuweYc SDfA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:cc; bh=W1tmd826wzxxw2dz8JHNgNRaQybNm4AACGIANRlyga0=; b=Nv7W638Nc3N5rKC/68BdSMGVeGfKjQdjusPVWczW6cml9vD4UDJCYPyP0xJHkiqKRP l5gPBg5CC4KTwpaNZTg5YNq7D/9/Dvn2dFLRcSptJP0d3z76oZwm3Mui6MAcTQo1XC3R j8EpjulKzCylONu/DU+2YsYNsEUKMMTEJ7HyjSl5w20K9co/Mx1uopXrFJztvkTQ9qJG 9727uvktMzt59DFBAkYBzxgYnKTAwqQjnloOz8tmgtvk6VhgHD9AVc1Kh1julmcat9fa d1m64SLYVApwAYA0Rg1Bt9GIlcCRwMd074x9z9rjmQH0e3WAmcNPbIMZMF/pRzSK4bQ8 eqfQ== X-Gm-Message-State: APjAAAVZ1iCYad0b+3l+NlArBzEFoNrnit4uB/qJ5bkUH+go8N3/1zIQ IBfzloCE0P21SPDSYBlYtiFDnGD34nHmGkL4Qan+I68iD0s= X-Received: by 2002:a5d:9046:: with SMTP id v6mt637573ioq.302.1575367116795; Tue, 03 Dec 2019 01:58:36 -0800 (PST) MIME-Version: 1.0 From: Fredrik Yhlen Date: Tue, 3 Dec 2019 10:56:28 +0100 Message-ID: Subject: Problems with USB on Raspberry Pi CM3, Linux 5.3 and 5.4 Cc: bcm-kernel-feedback-list@broadcom.com, netdev@vger.kernel.org, Stefan Wahren , nsaenzjulienne@suse.de, linux-usb@vger.kernel.org Content-Type: text/plain; charset="UTF-8" To: unlisted-recipients:; (no To-header on input) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi, The problems are especially easy to trigger via LTE modem in QMI mode using the qmi_wwan driver on mainline Linux 5.3. When pushing big bulk transfers over the modem it quickly triggers kernel oops in the network stack. I have based my defconfig of bcm2835_defconfig. In this example I use a SIM 7600e modem and run Linux 5.4: dwc2 3f980000.usb: dwc2_hc_chhltd_intr_dma: Channel 3 - ChHltd set, but reason is unknown Nov 28 14:07:29 kernel: dwc2 3f980000.usb: hcint 0x00000002, intsts 0x04600009 Nov 28 14:07:29 kernel: dwc2 3f980000.usb: dwc2_update_urb_state_abn(): trimming xfer length Nov 28 14:07:29 kernel: dwc2 3f980000.usb: dwc2_update_urb_state(): trimming xfer length Nov 28 14:07:29 kernel: 8<--- cut here --- Nov 28 14:07:29 kernel: Unable to handle kernel paging request at virtual address 60de655e Nov 28 14:07:29 kernel: pgd = b5a57262 Nov 28 14:07:29 kernel: [60de655e] *pgd=00000000 Nov 28 14:07:29 kernel: Internal error: Oops: 5 [#2] SMP ARM Nov 28 14:07:29 kernel: Modules linked in: qmi_wwan option cdc_wdm ftdi_sio usb_wwan usbserial snd_bcm2835(C) raspberrypi_hwmon vchiq(C) bcm2835_rng rng_core Nov 28 14:07:29 kernel: CPU: 2 PID: 599 Comm: wget Tainted: G D C 5.4.0+ #1 Nov 28 14:07:29 kernel: Hardware name: BCM2835 Nov 28 14:07:29 kernel: PC is at kfree_skb_list+0x1c/0x2c Nov 28 14:07:29 kernel: LR is at skb_release_data+0x50/0xc0 Nov 28 14:07:29 kernel: pc : [] lr : [] psr: 20000013 Nov 28 14:07:29 kernel: sp : ea55fcc0 ip : ea55fcd8 fp : ea55fcd4 Nov 28 14:07:29 kernel: r10: 00000000 r9 : ea55fe4c r8 : 0000000c Nov 28 14:07:29 kernel: r7 : ea619268 r6 : 00000000 r5 : ebe88000 r4 : ea619240 Nov 28 14:07:29 kernel: r3 : 00000000 r2 : 00000000 r1 : eaba9bb0 r0 : 60de655e Nov 28 14:07:29 kernel: Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Nov 28 14:07:29 kernel: Control: 10c5383d Table: 1f88806a DAC: 00000051 Nov 28 14:07:29 kernel: Process wget (pid: 599, stack limit = 0x90bfafcc) Nov 28 14:07:29 kernel: Stack: (0xea55fcc0 to 0xea560000) Nov 28 14:07:29 kernel: fcc0: ea619240 ebe88000 ea55fcfc ea55fcd8 c0620948 c06200bc ebe88000 00000b00 Nov 28 14:07:29 kernel: fce0: ebe88000 00000580 eaba9efc ea55fe4c ea55fd14 ea55fd00 c061ffd0 c0620904 Nov 28 14:07:29 kernel: fd00: ebe88000 00000b00 ea55fd2c ea55fd18 c061fff0 c061ffac ebe88000 00000b00 Nov 28 14:07:29 kernel: fd20: ea55fd44 ea55fd30 c0688220 c061ffe0 eaba9b00 00000b00 ea55fdf4 ea55fd48 Nov 28 14:07:29 kernel: fd40: c0688ec4 c06881b8 ea55fd64 ea55fd58 c0138790 c0136854 00000000 00000000 Nov 28 14:07:29 kernel: fd60: 00000000 00000000 00000001 00001500 00264ea7 00000001 20010093 00000004 Nov 28 14:07:29 kernel: fd80: c0d04e08 ea55fe04 00000051 7fffffff 00000004 00000051 c0d04e08 00000000 Nov 28 14:07:29 kernel: fda0: 00000000 beb83af4 00000004 00000000 00000000 c027d990 00000005 ea55fe04 Nov 28 14:07:29 kernel: fdc0: ea55fddc 1613dfbd c027d9cc eaba9b00 00000000 c0d04e08 ea55fe4c c06886d8 Nov 28 14:07:29 kernel: fde0: 00002000 00002000 ea55fe2c ea55fdf8 c06b67cc c06886e4 00000000 ea55fe00 Nov 28 14:07:29 kernel: fe00: 00000000 1613dfbd c06b6750 00002000 c0d04e08 ec7b5f80 ef566e40 00d73c38 Nov 28 14:07:29 kernel: fe20: ea55fe44 ea55fe30 c0612f08 c06b675c ea55feb8 00002000 ea55fea4 ea55fe48 Nov 28 14:07:29 kernel: fe40: c0612fc4 c0612ef4 c05c916c 00000000 00000000 00000004 00000b00 00001500 Nov 28 14:07:29 kernel: fe60: ea55feb0 00000001 ffffffff 00000000 00000000 00000000 ea55fed0 1613dfbd Nov 28 14:07:30 kernel: fe80: c0d04e08 c0d04e08 ea55ff50 ef566e40 00002000 00000000 ea55ff24 ea55fea8 Nov 28 14:07:30 kernel: fea0: c026a2cc c0612f34 00002000 ea55feb8 00d73c38 00002000 00000004 00000000 Nov 28 14:07:30 kernel: fec0: 00002000 ea55feb0 00000001 ffffffff ef566e40 00000000 00000000 00000000 Nov 28 14:07:30 kernel: fee0: 00000000 00000000 00000000 00000000 00000000 00000000 ea55ff5c 1613dfbd Nov 28 14:07:30 kernel: ff00: ef566e40 00000000 00002000 ef566e40 00d73c38 ea55ff50 ea55ff4c ea55ff28 Nov 28 14:07:30 kernel: ff20: c026a39c c026a21c ef566e40 00002000 ea55ff50 c0d04e08 ea55ff5c 00d73c38 Nov 28 14:07:30 kernel: ff40: ea55ff94 ea55ff50 c026a5c4 c026a30c 00000000 00000000 1ec321fc ef566e40 Nov 28 14:07:30 kernel: ff60: 00000000 1613dfbd beb83aec 00000074 00002000 00d73c38 00000003 c0101204 Nov 28 14:07:30 kernel: ff80: ea55e000 00000003 ea55ffa4 ea55ff98 c026a628 c026a558 00000000 ea55ffa8 Nov 28 14:07:30 kernel: ffa0: c0101000 c026a61c 00000074 00002000 00000004 00d73c38 00002000 00000000 Nov 28 14:07:30 kernel: ffc0: 00000074 00002000 00d73c38 00000003 0010e785 00000000 beb841d0 beb84208 Nov 28 14:07:30 kernel: ffe0: 00000003 beb83b88 b6c4c52f b6bd5746 20000030 00000004 00000000 00000000 Nov 28 14:07:30 kernel: Backtrace: Nov 28 14:07:30 kernel: [] (kfree_skb_list) from [] (skb_release_data+0x50/0xc0) Nov 28 14:07:30 kernel: r5:ebe88000 r4:ea619240 Nov 28 14:07:30 kernel: [] (skb_release_data) from [] (skb_release_all+0x30/0x34) Nov 28 14:07:30 kernel: r9:ea55fe4c r8:eaba9efc r7:00000580 r6:ebe88000 r5:00000b00 r4:ebe88000 Nov 28 14:07:30 kernel: [] (skb_release_all) from [] (__kfree_skb+0x1c/0x28) Nov 28 14:07:30 kernel: r5:00000b00 r4:ebe88000 Nov 28 14:07:30 kernel: [] (__kfree_skb) from [] (sk_eat_skb+0x74/0x88) Nov 28 14:07:30 kernel: r5:00000b00 r4:ebe88000 Nov 28 14:07:30 kernel: [] (sk_eat_skb) from [] (tcp_recvmsg+0x7ec/0x954) Nov 28 14:07:30 kernel: r5:00000b00 r4:eaba9b00 Nov 28 14:07:30 kernel: [] (tcp_recvmsg) from [] (inet_recvmsg+0x7c/0xa8) Nov 28 14:07:30 kernel: r10:00002000 r9:00002000 r8:c06886d8 r7:ea55fe4c r6:c0d04e08 r5:00000000 Nov 28 14:07:30 kernel: r4:eaba9b00 Nov 28 14:07:30 kernel: [] (inet_recvmsg) from [] (sock_recvmsg_nosec+0x20/0x24) Nov 28 14:07:30 kernel: r9:00d73c38 r8:ef566e40 r7:ec7b5f80 r6:c0d04e08 r5:00002000 r4:c06b6750 Nov 28 14:07:30 kernel: [] (sock_recvmsg_nosec) from [] (sock_read_iter+0x9c/0xdc) Nov 28 14:07:30 kernel: r5:00002000 r4:ea55feb8 Nov 28 14:07:30 kernel: [] (sock_read_iter) from [] (__vfs_read+0xbc/0xf0) Nov 28 14:07:30 kernel: r8:00000000 r7:00002000 r6:ef566e40 r5:ea55ff50 r4:c0d04e08 Nov 28 14:07:30 kernel: [] (__vfs_read) from [] (vfs_read+0x9c/0xb8) Nov 28 14:07:30 kernel: r8:ea55ff50 r7:00d73c38 r6:ef566e40 r5:00002000 r4:00000000 Nov 28 14:07:30 kernel: [] (vfs_read) from [] (ksys_read+0x78/0xc4) Nov 28 14:07:30 kernel: r9:00d73c38 r8:ea55ff5c r7:c0d04e08 r6:ea55ff50 r5:00002000 r4:ef566e40 Nov 28 14:07:30 kernel: [] (ksys_read) from [] (sys_read+0x18/0x1c) Nov 28 14:07:30 kernel: r10:00000003 r9:ea55e000 r8:c0101204 r7:00000003 r6:00d73c38 r5:00002000 Nov 28 14:07:30 kernel: r4:00000074 Nov 28 14:07:30 kernel: [] (sys_read) from [] (ret_fast_syscall+0x0/0x54) Nov 28 14:07:30 kernel: Exception stack(0xea55ffa8 to 0xea55fff0) Nov 28 14:07:30 kernel: ffa0: 00000074 00002000 00000004 00d73c38 00002000 00000000 Nov 28 14:07:30 kernel: ffc0: 00000074 00002000 00d73c38 00000003 0010e785 00000000 beb841d0 beb84208 Nov 28 14:07:30 kernel: ffe0: 00000003 beb83b88 b6c4c52f b6bd5746 Nov 28 14:07:30 kernel: Code: e52de004 e8bd4000 e3500000 089da830 (e5904000) Nov 28 14:07:30 kernel: ---[ end trace 813694f10fff952d ]--- Linux 5.3: [ 178.201655] dwc2 3f980000.usb: dwc2_hc_chhltd_intr_dma: Channel 5 - ChHltd set, but reason is unknown [ 178.215388] dwc2 3f980000.usb: hcint 0x00000002, intsts 0x04200009 [ 178.223894] dwc2 3f980000.usb: dwc2_update_urb_state_abn(): trimming xfer length [ 178.233735] dwc2 3f980000.usb: dwc2_update_urb_state(): trimming xfer length [ 178.245841] 8<--- cut here --- [ 178.251360] Unable to handle kernel paging request at virtual address 97b1527b [ 178.261121] pgd = 2195337a [ 178.266424] [97b1527b] *pgd=00000000 [ 178.272452] Internal error: Oops: 5 [#1] SMP ARM [ 178.279433] Modules linked in: can_raw can option usb_wwan qmi_wwan usbserial cdc_wdm snd_bcm2835(C) r8188eu(C) lib80211 raspberrypi_hwmon mcp251x can_dev vchiq(C) bcm2835_rng rng_core [ 178.303651] CPU: 0 PID: 2638 Comm: wget Tainted: G C 5.3.0+ #1 [ 178.313557] Hardware name: BCM2835 [ 178.319755] PC is at kfree_skb_list+0x1c/0x2c [ 178.326974] LR is at skb_release_data+0xd4/0x144 [ 178.334410] pc : [] lr : [] psr: a0070013 [ 178.343526] sp : e9b93cd8 ip : e9b93cf0 fp : e9b93cec [ 178.351609] r10: 00000000 r9 : e98a6ff4 r8 : e4abd568 [ 178.359679] r7 : 00000000 r6 : 00000000 r5 : e9824b40 r4 : e4abd540 [ 178.369071] r3 : 00000000 r2 : 00002180 r1 : 000019c0 r0 : 97b1527b [ 178.378452] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none [ 178.388453] Control: 10c5383d Table: 24ae806a DAC: 00000051 [ 178.397040] Process wget (pid: 2638, stack limit = 0xf64efb7c) [ 178.405711] Stack: (0xe9b93cd8 to 0xe9b94000) [ 178.412933] 3cc0: e4abd540 e9824b40 [ 178.426773] 3ce0: e9b93d14 e9b93cf0 c065d4e4 c065caf8 e9824b40 e9824b40 00000fc6 00000542 [ 178.440680] 3d00: 00000000 e98a6ff4 e9b93d2c e9b93d18 c065c9ec c065d41c e9824b40 e9824b40 [ 178.454626] 3d20: e9b93d44 e9b93d30 c065ca0c c065c9c8 e98a6c00 e9824b40 e9b93df4 e9b93d48 [ 178.468790] 3d40: c06cb7c0 c065c9fc 00000001 ef461c00 00000058 ef405180 00000000 00000000 [ 178.483125] 3d60: 00000000 00000001 0000103a e9b93e44 c0d6c440 0002af5c e9b93dbc e9b93d88 [ 178.497627] 3d80: c025c6cc c0238374 fffffffc 7fffffff c016a878 eff48b80 40080013 00000002 [ 178.512377] 3da0: e9b93dc0 2ecfe000 00000001 0030f231 e9b93e04 e9b93dc0 c025cb98 c025c5c8 [ 178.527149] 3dc0: 00000000 19ad9c1c e99fe240 c0d04c08 e9b93e44 c06caf44 e86d2640 e9af16c0 [ 178.542045] 3de0: 00000000 00000000 e9b93e24 e9b93df8 c06f9690 c06caf50 00000000 e9b93e00 [ 178.557224] 3e00: 00000000 19ad9c1c eaf5c000 c06f95c8 00002000 c0d04c08 e9b93e3c e9b93e28 [ 178.572623] 3e20: c064f52c c06f95d4 e9b93eb0 00002000 e9b93e9c e9b93e40 c064f5cc c064f510 [ 178.588285] 3e40: e9b93e6c 00000000 00000000 00000004 00000fc6 0000103a e9b93ea8 00000001 [ 178.604209] 3e60: e9b93ed0 00000000 00000000 00000000 e9b93ec8 19ad9c1c c0d04c08 e9af16c0 [ 178.620279] 3e80: 00000000 c0d04c08 e9b93f58 00002000 e9b93f24 e9b93ea0 c027fbf4 c064f53c [ 178.636547] 3ea0: 00002000 c0d04c08 01b87818 00002000 00000004 00000000 00002000 e9b93ea8 [ 178.653024] 3ec0: 00000001 e9b93ed0 e9af16c0 00000000 00000000 00000000 00000000 00000000 [ 178.669793] 3ee0: 00000000 00000000 00000000 00000000 e9b93f14 19ad9c1c c017cf00 e9af16c0 [ 178.686390] 3f00: 00002000 00000001 01b87818 e9b93f58 00000000 00002000 e9b93f54 e9b93f28 [ 178.702925] 3f20: c027fcc8 c027fa9c c029f580 c029f4d8 e9af16c0 00002000 e9b93f58 c0d04c08 [ 178.720034] 3f40: e9af16c0 01b87818 e9b93f94 e9b93f58 c027ffac c027fc34 00000000 00000000 [ 178.736549] 3f60: c0177f4c 19ad9c1c b6c8d518 00000074 00002000 01b87818 00000003 c0101204 [ 178.753041] 3f80: e9b92000 00000003 e9b93fa4 e9b93f98 c0280028 c027ff4c 00000000 e9b93fa8 [ 178.769535] 3fa0: c0101000 c028001c 00000074 00002000 00000004 01b87818 00002000 00000000 [ 178.786022] 3fc0: 00000074 00002000 01b87818 00000003 00013fbf 00000000 bec10900 bec10938 [ 178.802511] 3fe0: 00000003 bec102b8 b6c8d52f b6c16746 20070030 00000004 00000000 00000000 [ 178.818997] Backtrace: [ 178.825569] [] (kfree_skb_list) from [] (skb_release_data+0xd4/0x144) [ 178.841844] r5:e9824b40 r4:e4abd540 [ 178.849405] [] (skb_release_data) from [] (skb_release_all+0x30/0x34) [ 178.865543] r9:e98a6ff4 r8:00000000 r7:00000542 r6:00000fc6 r5:e9824b40 r4:e9824b40 [ 178.877334] [] (skb_release_all) from [] (__kfree_skb+0x1c/0x28) [ 178.889314] r5:e9824b40 r4:e9824b40 [ 178.896997] [] (__kfree_skb) from [] (tcp_recvmsg+0x87c/0xa0c) [ 178.908524] r5:e9824b40 r4:e98a6c00 [ 178.916015] [] (tcp_recvmsg) from [] (inet_recvmsg+0xc8/0xfc) [ 178.927425] r10:00000000 r9:00000000 r8:e9af16c0 r7:e86d2640 r6:c06caf44 r5:e9b93e44 [ 178.939423] r4:c0d04c08 [ 178.945786] [] (inet_recvmsg) from [] (sock_recvmsg+0x28/0x2c) [ 178.957212] r6:c0d04c08 r5:00002000 r4:c06f95c8 [ 178.965607] [] (sock_recvmsg) from [] (sock_read_iter+0x9c/0xdc) [ 178.977157] r5:00002000 r4:e9b93eb0 [ 178.984455] [] (sock_read_iter) from [] (__vfs_read+0x164/0x198) [ 178.995976] r8:00002000 r7:e9b93f58 r6:c0d04c08 r5:00000000 r4:e9af16c0 [ 179.006419] [] (__vfs_read) from [] (vfs_read+0xa0/0x110) [ 179.017274] r10:00002000 r9:00000000 r8:e9b93f58 r7:01b87818 r6:00000001 r5:00002000 [ 179.028807] r4:e9af16c0 [ 179.034940] [] (vfs_read) from [] (ksys_read+0x6c/0xd0) [ 179.045638] r9:01b87818 r8:e9af16c0 r7:c0d04c08 r6:e9b93f58 r5:00002000 r4:e9af16c0 [ 179.057046] [] (ksys_read) from [] (sys_read+0x18/0x1c) [ 179.067628] r10:00000003 r9:e9b92000 r8:c0101204 r7:00000003 r6:01b87818 r5:00002000 [ 179.079075] r4:00000074 [ 179.085123] [] (sys_read) from [] (ret_fast_syscall+0x0/0x54) [ 179.096199] Exception stack(0xe9b93fa8 to 0xe9b93ff0) [ 179.104841] 3fa0: 00000074 00002000 00000004 01b87818 00002000 00000000 [ 179.120293] 3fc0: 00000074 00002000 01b87818 00000003 00013fbf 00000000 bec10900 bec10938 [ 179.136135] 3fe0: 00000003 bec102b8 b6c8d52f b6c16746 [ 179.145377] Code: e52de004 e8bd4000 e3500000 089da830 (e5904000) [ 179.155709] ---[ end trace b3bd3328793c3068 ]--- There is always at least one USB channel that gets halted in the dwc2 controller driver(modem sits on the USB bus) just before the kernel oops happens. There seems to be some weird race condition or concurrency issue going on when a USB channel gets halted and the driver attempts to handle it. I can trigger it easily by just wget a big file - it usually happens within 40 seconds or so. I did a quick ugly fix, just for experimenting, and somehow this seems to fix it: ------------------------------------------------------------------------------------------------------------------ --- linux-5.3/drivers/usb/dwc2/hcd_intr.c 2019-10-11 22:12:45.051690563 +0200 +++ linux-5.3.new/drivers/usb/dwc2/hcd_intr.c 2019-12-02 15:50:31.895458866 +0100 @@ -1974,7 +1974,7 @@ chan->hcint); error: /* Failthrough: use 3-strikes rule */ - qtd->error_count++; + qtd->error_count = 4; dwc2_update_urb_state_abn(hsotg, chan, chnum, qtd->urb, qtd, DWC2_HC_XFER_XACT_ERR); dwc2_hcd_save_data_toggle(hsotg, chan, chnum, qtd); ------------------------------------------------------------------------------------------------------------------ I can still occasionally see: dwc2 3f980000.usb: dwc2_hc_chhltd_intr_dma: Channel 5 - ChHltd set, but reason is unknown But now it doesn't crash when doing wget on big files or when doing full updates over the modem. Why does this work? Thanks! Best regards, Fredrik Yhlen