Created attachment 176011 [details] output of dmesg on kernel 4.1.0-040100rc2-generic ExpressCard type USB3.0 adapter for laptop does not work on hotplug with the current mainline kernel 4.1.0-040100rc2-generic – devices attached to it do not get reported by the system as attached and cannot get mounted/function. The hotplug does work on an older kernel (giving 3x read spead from an external USB 3.0 drive), so it looks like a regression. However, when booted with the device attached, the adapter and the attached devices do function properly - the attached devices work fine both coldplugged and hotplugged. The adapter in question: 2 Port USB3.0 expressCard, UNEC UPD720202 Chip see here for description http://www.amazon.co.uk/SuperSpeed-compatible-transfer-Notebook-internal/dp/B00K49TNUU
Created attachment 176021 [details] output of lspci -vv on kernel 4.1.0-040100rc2-generic
Created attachment 176071 [details] output of dmesg on 3.13.0-031300-generic (i386 machine) Latest kernel where hotplug is known to work - 3.13.0-031300-generic (mainline kernel; Ubuntu 3.13.0 kernel also works). I am attaching dmesg and lspci output generated on an older machine (Asus A8F, i386 kernel architecture, while the problem with v4 kernel was detected on a amd64 machine - Lenovo thinkpad x220t).
Created attachment 176081 [details] output of lspci -vv on 3.13.0-031300-generic (i386 machine)