Hello,
I'm experiencing problems with our USB-CAN-hardware in a test scenario only when being attached to the ehci root-hub.
When the device is enumerated and has its USB address the driver is bound and the can interface is started. So far so good. If there is a status request timeout the module firmware disconnects itself from the bus, thus reattaching to the bus, getting a new USB device address and so on...
Doing this in a loops lead eventually to this error messages:
> kernel: usb 1-1.1.6.1: new full-speed USB device number 21 using ehci-pci
> kernel: usb 1-1.1.6.1: device descriptor read/64, error -110
> kernel: usb 1-1.1.6.1: device descriptor read/64, error -110
> kernel: usb 1-1.1.6.1: new full-speed USB device number 22 using ehci-pci
> kernel: usb 1-1.1.6.1: device descriptor read/64, error -110
> kernel: usb 1-1.1.6.1: device descriptor read/64, error -110
> kernel: usb 1-1.1.6.1: new full-speed USB device number 23 using ehci-pci
> kernel: usb 1-1.1.6.1: device not accepting address 23, error -110
> kernel: usb 1-1.1.6.1: new full-speed USB device number 24 using ehci-pci
> kernel: usb 1-1.1.6.1: device not accepting address 24, error -110
> kernel: hub 1-1.1.6:1.0: unable to enumerate USB device on port 1
At this point the device never gets back to the bus itself. Either the whole hardware has to be power-cycled or the USB cable detached and attached again.
The device is connected as follows (if done correctly)
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/2p, 480M
|__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/8p, 480M
|__ Port 6: Dev 14, If 0, Class=Hub, Driver=hub/1p, 480M
|__ Port 1: Dev 16, If 0, Class=Vendor Specific Class, Driver=, 12M
Now the funny thing: This doesn't occur if
1. The device with its internal hub (Dev 14 above) is attached to xHCI host
2. There is an Full-Speed-Hub before the device
3. The device is attached to a OHCI host
The error occurs about 3-6 min after start while the test cases where it didn't happen run for longer than 1 hour.
So the problem seems to occur only when the hub is connected with high-speed to any hub on an ehci bus.
Has somebody an idea what might have gone wrong here? It seems the internal hub has problems with Transaction Translators. But why does this only happen when attached to ehci? Is this maybe a driver problem?
I did some tests on 3.11.4 and some on 3.10.7 and both showed same results.
Best regards,
Alexander
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