On Sat, 16 Apr 2011, Marcel wrote: > Hi, > > > > Most likely the root cause is a hardware bug in the Atmel G45. > > > However the only way to prove this would be to replace the G45 with a > > > different kind of system. > > I think I found something on this : > > The G45 has a 2 port USB host and 1 USB device connection. > The device connection gets enabled by setting EN_UDPHS. Does the device connection share the second host port, or does it use a separate port? How many ports are there altogether? > Linux reports at startup : > hub 1-0:1.0: 2 ports detected. > > Once Linux is started I start my gadget device driver. This enabled USB device > and I suppose it would disable port 2. Starting USB device earlier than host > doesn't change anything. If the port is shared, then yes, one would expect port 2 to be disabled. Otherwise there is no reason to disable it, as far as I know. > Port 1 is in use, port 2 is not. It is at least not accessible from outside > the G45. What do you mean? Why not? > I don't see how to disable it in the G45 spec though. It just speaks > about enabling USB device. Anyway, if it's still active in the G45 but not > accessible from outside I guess it could be considered a bug in the hardware. > > Is there a way to disable port2 in Linux ? You should ask the people who maintain the Atmel drivers. However, if nothing is connected to that port then it shouldn't ever do anything. > While I communicate over the USB device, I receive the following : > > hub 1-0:1.0: state 7 ports 2 chg 0000 evt 0004 > atmel-ehci atmel-ehci: GetStatus port 2 status 001803 POWER sig=j CSC CONNECT > hub 1-0:1.0: port 2, status 0501, change 0001, 480 Mb/s > usb 1-2: USB disconnect, address 2 > usb 1-2.1: USB disconnect, address 4 > usb 1-2.1: unregistering device > usb 1-2.1: usb_disable_device nuking all URBs > usb 1-2.1: unregistering interface 1-2.1:1.0 > > Line 3 seems to indicate a change on a port that I don't use or I'm > misinterpreting the message. Maybe you're misinterpreting the message. This says that a hub was connected to port 2 (and some other device was connected to port 1 on that hub); the message indicates that it got disconnected. > btw, I have a way to replace my g45 by another MCU. If I get nowhere tomorrow > with this, I will order one and try it. 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
