Hi, Thanks for your reply. On Wed, Jun 19, 2013 at 11:17 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Wed, 19 Jun 2013, Ming Lei wrote: > >> Hi, >> >> Recently, there is one bug report from Ubuntu community: >> >> USB 2.0 Ports Dont Work on Sony Vaio Laptop >> >> and the problem exists on upstream kernel too. >> >> The built-in two USB 2.0 devices can be recognized correctly, >> but external devices can't be recognized when the device is >> connected to USB 2.0 port. Also, the USB 2.0 bus can be waken >> up successfully via /sys/bus/devices/.../power/control, but still can't >> find external connected devices, and no any 'dmesg' log with >> CONFIG_USB_DEBUG enabled after the device is plugged into >> 2.0 ports. >> >> See detailed log in below link: >> >> https://bugs.launchpad.net/bugs/1172908 >> >> No such problem on Windows. > > There's a good chance this problem was caused by a change in the > xhci-hcd driver. I am wondering why xhci-hcd may cause the problem since the affected hub is 'Intel Corp. Integrated Rate Matching Hub' which is connected to EHCI root hub. Also tests showed that there is power provided by port of the 'Integrated Rate Matching Hub', but can't detect connection. > Anyway, it looks like the best way of finding the problem is git > bisect. Thanks, -- Ming Lei -- 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
