Hello, Now that "unplugging" the userland process does not kill the kernel, I tried unplugging the cable in the same starting conditions (two submitted AIO read transfers, host having enabled the device, but no data transfer actually happening). And I got below WARNING. Sadly, the error goes away when enabling traces (110 being ETIMEDOUT, this could explain...) so I resorted to an ad-hoc printk (first line below). Platform CPU is slow: dual-core intel atom 500MHz. But reading the code, a slow CPU would seem to be an advantage, as the timeout is counted in loop iterations (busy loop on dwc3_readl), and apparently not as wall-clock time. [ 81.326172] dwc3_send_gadget_ep_cmd -> -110 [ 81.326273] ------------[ cut here ]------------ [ 81.335341] WARNING: CPU: 0 PID: 1874 at drivers/usb/dwc3/gadget.c:2627 dwc3_stop_active_transfer.constprop.23+0x69/0xc0 [dwc3] [ 81.347094] Modules linked in: usb_f_fs libcomposite configfs bnep btsdio bluetooth ecdh_generic brcmfmac brcmutil dwc3 intel_powerclamp coretemp ulpi kvm_intel udc_core kvm irqbypass crc32_pclmul crc32c_intel pcbc dwc3_pci aesni_intel aes_i586 crypto_simd cryptd ehci_pci ehci_hcd basincove_gpadc industrialio gpio_keys usbcore usb_common [ 81.378142] CPU: 0 PID: 1874 Comm: irq/34-dwc3 Not tainted 4.14.0-edison+ #119 [ 81.385545] Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 2015.01.21:18.19.48 [ 81.394548] task: f5b1be00 task.stack: f420a000 [ 81.399219] EIP: dwc3_stop_active_transfer.constprop.23+0x69/0xc0 [dwc3] [ 81.406086] EFLAGS: 00010086 CPU: 0 [ 81.409672] EAX: 0000001f EBX: f5729800 ECX: c132a2a2 EDX: 00000000 [ 81.416096] ESI: f4054014 EDI: f41cf400 EBP: f420be10 ESP: f420bdf4 [ 81.422521] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 [ 81.428061] CR0: 80050033 CR2: b7a3f000 CR3: 01d94000 CR4: 001006d0 [ 81.434483] Call Trace: [ 81.437063] __dwc3_gadget_ep_disable+0xa3/0x2b0 [dwc3] [ 81.442438] ? _raw_spin_lock_irqsave+0x32/0x40 [ 81.447135] dwc3_gadget_ep_disable+0xbf/0xe0 [dwc3] [ 81.452269] usb_ep_disable+0x1c/0xd0 [udc_core] [ 81.457048] ffs_func_eps_disable.isra.15+0x3b/0x90 [usb_f_fs] [ 81.463070] ffs_func_set_alt+0x7d/0x310 [usb_f_fs] [ 81.468132] ffs_func_disable+0x14/0x20 [usb_f_fs] [ 81.473075] reset_config+0x5b/0x90 [libcomposite] [ 81.478023] composite_disconnect+0x2b/0x50 [libcomposite] [ 81.483685] dwc3_disconnect_gadget+0x39/0x50 [dwc3] [ 81.488808] dwc3_gadget_disconnect_interrupt+0x21b/0x250 [dwc3] [ 81.495014] dwc3_thread_interrupt+0x2a8/0xf70 [dwc3] [ 81.500219] ? __schedule+0x78c/0x7e0 [ 81.504027] irq_thread_fn+0x18/0x30 [ 81.507715] ? irq_thread+0xb7/0x180 [ 81.511400] irq_thread+0x111/0x180 [ 81.515000] ? irq_finalize_oneshot+0xe0/0xe0 [ 81.519490] ? wake_threads_waitq+0x30/0x30 [ 81.523806] kthread+0x107/0x110 [ 81.527131] ? disable_percpu_irq+0x50/0x50 [ 81.531439] ? kthread_stop+0x150/0x150 [ 81.535397] ret_from_fork+0x19/0x24 [ 81.539136] Code: 89 d8 c7 45 ec 00 00 00 00 c7 45 f0 00 00 00 00 c7 45 f4 00 00 00 00 e8 56 ef ff ff 85 c0 74 12 50 68 b9 1c 14 f8 e8 64 0f f7 c8 <0f> ff 58 5a 8d 76 00 8b 83 98 00 00 00 c6 83 a0 00 00 00 00 83 [ 81.559295] ---[ end trace f3133eec81a473b8 ]--- [ 81.591665] dwc3 dwc3.1.auto: request f5abd960 was not queued to ep2out [ 81.598618] ffs_aio_cancel_worker: -22 Regards, -- Vincent Pelletier -- 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
