In host mode,while continuously connecting and disconnecting a USB device,sometimes enumeration does not happen(kernel 3.0.31).We see that the hub_thread is blocked in the schedule() function.The following is the function trace: [ 34.859924] task PC stack pid father [ 34.865203] khubd D c05e9cb4 0 420 2 0x00000000 [ 34.871704] [<c05e9cb4>] (__schedule+0x3d4/0x934) from [<c05ea388>] (schedule+0x58/0x70) [ 34.879882] [<c05ea388>] (schedule+0x58/0x70) from [<c034ab70>] (rpm_resume+0x130/0x50c) [ 34.888031] [<c034ab70>] (rpm_resume+0x130/0x50c) from [<c034acb4>] (rpm_resume+0x274/0x50c) [ 34.896545] [<c034acb4>] (rpm_resume+0x274/0x50c) from [<c034bc70>] (__pm_runtime_resume+0x58/0x70) [ 34.905670] [<c034bc70>] (__pm_runtime_resume+0x58/0x70) from [<c03ae220>] (usb_autopm_get_interface+0x28/0x7c) [ 34.915832] [<c03ae220>] (usb_autopm_get_interface+0x28/0x7c) from [<c03a6428>] (hub_thread+0x118/0x15bc) [ 34.925506] [<c03a6428>] (hub_thread+0x118/0x15bc) from [<c00b7af0>] (kthread+0x94/0x9c) [ 34.933685] [<c00b7af0>] (kthread+0x94/0x9c) from [<c005e208>] (kernel_thread_exit+0x0/0x8) This happens in the case wherein there is a race condition between the suspend (following the disconnect) and the resume (on re-connection).Was a similar issue observed in this kernel? Are there any patches available? Also,this issue is not seen on kernel3.4.However ,I require some suggestions to resolve this issue on kernel3.0.31. Kindly provide appropriate feedback. -- 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