Hi Mathias, On 18/08/15 13:39, Roger Quadros wrote: > Hi, > > Plugging and unplugging a USB-OTG adapter with a USB device into a > am437x-gp-evm dual-role port (USB1) causes XHCI to malfunction > and USB device to be no longer detected after a few iterations. > > The triggering case is so > 1) USB1 in peripheal mode > 2) plug OTG adapter with USB device > 3) USB1 switches to host mode > 4) Detects new USB device > 5) unplug OTG adapter > 6) OTG core tries to remove host controller while new device > is being processed. > > At 6 some races are observed in the XHCI driver causing it to > malfunction. See kernel log at the end of this mail. > > This series tries to address some of the issues. > Althouth it is not 100% fool proof yet and XHCI can still get > stuck up for a few seconds occasionally, it did recover always > in a max of 10 seconds and the USB device was enumerated after > that. > > During a dual-role switch, usb_remove_hcd() and usb_add_hcd() > will be called consecutively for both Shared and Primary > HCDs. This can happen asynchronously and we have to be prepared > for it. > Even after this series I do occasionally see a delay of 5 seconds during adapter detach. (please see kernel log below). Is it possible to further optimize so that when xhci_stop is called we don't depend entirely on timeout timers to stop queued commands? [ 106.301771] xhci-hcd xhci-hcd.0.auto: xHCI Host Controller [ 106.307480] xhci-hcd xhci-hcd.0.auto: new USB bus registered, assigned bus number 3 [ 106.320818] xhci-hcd xhci-hcd.0.auto: hcc params 0x0238f06d hci version 0x100 quirks 0x00010010 [ 106.329809] xhci-hcd xhci-hcd.0.auto: irq 253, io mem 0x48390000 [ 106.337587] usb usb3: New USB device found, idVendor=1d6b, idProduct=0002 [ 106.344455] usb usb3: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 106.352769] usb usb3: Product: xHCI Host Controller [ 106.357813] usb usb3: Manufacturer: Linux 4.1.6-01054-g496f557-dirty xhci-hcd [ 106.365012] usb usb3: SerialNumber: xhci-hcd.0.auto [ 106.381914] hub 3-0:1.0: USB hub found [ 106.390765] hub 3-0:1.0: 1 port detected [ 106.400732] xhci-hcd xhci-hcd.0.auto: xHCI Host Controller [ 106.407492] xhci-hcd xhci-hcd.0.auto: new USB bus registered, assigned bus number 4 [ 106.421396] usb usb4: We don't know the algorithms for LPM for this host, disabling LPM. [ 106.436701] usb usb4: New USB device found, idVendor=1d6b, idProduct=0003 [ 106.443577] usb usb4: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 106.454456] usb usb4: Product: xHCI Host Controller [ 106.460990] usb usb4: Manufacturer: Linux 4.1.6-01054-g496f557-dirty xhci-hcd [ 106.473275] usb usb4: SerialNumber: xhci-hcd.0.auto [ 106.502263] hub 4-0:1.0: USB hub found [ 106.511431] hub 4-0:1.0: 1 port detected [ 106.715490] usb 3-1: new high-speed USB device number 2 using xhci-hcd [ 106.822091] xhci-hcd xhci-hcd.0.auto: remove, state 4 [ 106.827261] usb usb4: USB disconnect, device number 1 [ 111.845544] xhci-hcd xhci-hcd.0.auto: Command completion event does not match command [ 111.853518] xhci-hcd xhci-hcd.0.auto: Timeout while waiting for setup device command [ 111.888145] xhci-hcd xhci-hcd.0.auto: Host not halted after 16000 microseconds. [ 111.895528] xhci-hcd xhci-hcd.0.auto: Host controller not halted, aborting reset. [ 111.905732] xhci-hcd xhci-hcd.0.auto: USB bus 4 deregistered [ 111.912598] xhci-hcd xhci-hcd.0.auto: remove, state 1 [ 111.918695] usb usb3: USB disconnect, device number 1 [ 112.125544] usb 3-1: device descriptor read/all, error -22 [ 112.131106] usb usb3-port1: couldn't allocate usb_device [ 112.140019] xhci-hcd xhci-hcd.0.auto: USB bus 3 deregistered cheers, -roger -- 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
