xhci_hcd: WARN Event TRB for slot 6 ep 4 with no TDs queued?

[Jan Kiszka]

Hi,

I'm getting

xhci_hcd 0000:00:14.0: WARN Event TRB for slot 6 ep 4 with no TDs queued?

on each interaction with my built-in CCID smartcard reader (Celsius
H730). The device is working fine otherwise, just the log fills up.
What's the reason? What can be done about it?

Find lsusb -v of the reader below.

Jan

---

Bus 001 Device 006: ID 0b97:7772 O2 Micro, Inc. OZ776 CCID Smartcard Reader
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               1.10
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0
  bDeviceProtocol         0
  bMaxPacketSize0        64
  idVendor           0x0b97 O2 Micro, Inc.
  idProduct          0x7772 OZ776 CCID Smartcard Reader
  bcdDevice            1.10
  iManufacturer           1 O2
  iProduct                2 O2Micro CCID SC Reader
  iSerial                 0
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           93
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0
    bmAttributes         0xe0
      Self Powered
      Remote Wakeup
    MaxPower                0mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           3
      bInterfaceClass        11 Chip/SmartCard
      bInterfaceSubClass      0
      bInterfaceProtocol      0
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x03  EP 3 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0003  1x 3 bytes
        bInterval             255
      ChipCard Interface Descriptor:
        bLength                54
        bDescriptorType        33
        bcdCCID              1.00
        nMaxSlotIndex           0
        bVoltageSupport         7  5.0V 3.0V 1.8V
        dwProtocols             3  T=0 T=1
        dwDefaultClock       4000
        dwMaxiumumClock      4000
        bNumClockSupported      0
        dwDataRate           9600 bps
        dwMaxDataRate      307200 bps
        bNumDataRatesSupp.      0
        dwMaxIFSD             254
        dwSyncProtocols  00000000
        dwMechanical     00000000
        dwFeatures       00000030
          Auto clock change
          Auto baud rate change
        dwMaxCCIDMsgLen       271
        bClassGetResponse      00
        bClassEnvelope         00
        wlcdLayout           none
        bPINSupport             0
        bMaxCCIDBusySlots       1
Device Status:     0x0001
  Self Powered

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