On Sat, 21 Nov 2009, Vladimir Komendantsky wrote: > Hi, > > I'm trying to make linux to connect to a USB 2.0 device at high speed > (480 Mb/s) and having difficulties understanding dmesg logs. There is > a point in the logs (quoted below) when the device is first tried for > ehci compatibility, unsuccessfully, and then it is connected to an > uhci hub. > > The device is USB 1.1 compliant and works well in Linux. However, 12 > Mb/s is an insufficient speed, which is solved in Windows by > manufacturer device drivers. Is there a reference on this kind of a > problem? Maybe there is a way to make Linux connect at high speed > without spending time understanding Windows drivers, given that it > already works with USB 1.1? > > [ 1666.291787] usb usb2: usb resume > [ 1666.291799] ehci_hcd 0000:00:1d.7: resume root hub > [ 1666.412345] ehci_hcd 0000:00:1d.7: port 2 full speed --> companion This line indicates that your device is not completing the high-speed handshake and thus is failing to connect at high speed. There is a hardware problem either in the device or in the EHCI controller or in the connecting cable. Alan Stern -- 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
