ucom modem issue on recent RELENG_8

[Mike Tancsa]

Hi,
	I have run into a problem where ucom no longer works with a recent kernel from this past week on RELENG_8. I tried the same setup with RELENG_8 from Feb 14th and it works as expected.  I am about to start narrowing it down but was wondering if any one had any hints as to what to try ?  The symptoms are that large packets fail.

e.g. on a dial connection, if I do 
ping -s 900 <remote ip>
it works, although its quite slow with higher than normal latency.
if I increase the packet size to 1000, packets fail, or they take upwards of 8 seconds to traverse the link if they ever get through.  Using an external modem on the serial port works just fine, so it seems related to just usb ucom devices.  (I havent tried u3g yet)

The kernel from Feb 14th works as expected. From April 18th, it does not.

This is on an alix board

ohci0 at pci0:0:15:4:      class=0x0c0310 card=0x20941022 chip=0x20941022 rev=0x02 hdr=0x00
    vendor     = 'Advanced Micro Devices (AMD)'
    device     = 'CS5536 OHCI USB Host Controller (CS5536)'
    class      = serial bus
    subclass   = USB
    cap 01[40] = powerspec 2  supports D0 D3  current D0
ehci0 at pci0:0:15:5:      class=0x0c0320 card=0x20951022 chip=0x20951022 rev=0x02 hdr=0x00
    vendor     = 'Advanced Micro Devices (AMD)'
    device     = 'CS5536 EHCI USB Host Controller (CS5536)'
    class      = serial bus
    subclass   = USB
    cap 01[40] = powerspec 2  supports D0 D3  current D0

ugen1.2: <USB Modem U.S.Robotics> at usbus1, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON


 Configuration index 0

    bLength = 0x0009 
    bDescriptorType = 0x0002 
    wTotalLength = 0x0043 
    bNumInterfaces = 0x0002 
    bConfigurationValue = 0x0002 
    iConfiguration = 0x0000  <no string>
    bmAttributes = 0x0080 
    bMaxPower = 0x00b4 

    Interface 0
      bLength = 0x0009 
      bDescriptorType = 0x0004 
      bInterfaceNumber = 0x0000 
      bAlternateSetting = 0x0000 
      bNumEndpoints = 0x0001 
      bInterfaceClass = 0x0002 
      bInterfaceSubClass = 0x0002 
      bInterfaceProtocol = 0x0001 
      iInterface = 0x0005  <AltIf0>

      Additional Descriptor

      bLength = 0x05
      bDescriptorType = 0x24
      bDescriptorSubType = 0x00
       RAW dump: 
       0x00 | 0x05, 0x24, 0x00, 0x01, 0x10


      Additional Descriptor

      bLength = 0x05
      bDescriptorType = 0x24
      bDescriptorSubType = 0x01
       RAW dump: 
       0x00 | 0x05, 0x24, 0x01, 0x03, 0x01


      Additional Descriptor

      bLength = 0x05
      bDescriptorType = 0x24
      bDescriptorSubType = 0x06
       RAW dump: 
       0x00 | 0x05, 0x24, 0x06, 0x00, 0x01


      Additional Descriptor

      bLength = 0x04
      bDescriptorType = 0x24
      bDescriptorSubType = 0x02
       RAW dump: 
       0x00 | 0x04, 0x24, 0x02, 0x06


     Endpoint 0
        bLength = 0x0007 
        bDescriptorType = 0x0005 
        bEndpointAddress = 0x0082  <IN>
        bmAttributes = 0x0003  <INTERRUPT>
        wMaxPacketSize = 0x0010 
        bInterval = 0x000a 
        bRefresh = 0x0000 
        bSynchAddress = 0x0000 


    Interface 1
      bLength = 0x0009 
      bDescriptorType = 0x0004 
      bInterfaceNumber = 0x0001 
      bAlternateSetting = 0x0000 
      bNumEndpoints = 0x0002 
      bInterfaceClass = 0x000a 
      bInterfaceSubClass = 0x0000 
      bInterfaceProtocol = 0x0000 
      iInterface = 0x0005  <AltIf0>

     Endpoint 0
        bLength = 0x0007 
        bDescriptorType = 0x0005 
        bEndpointAddress = 0x0001  <OUT>
        bmAttributes = 0x0002  <BULK>
        wMaxPacketSize = 0x0200 
        bInterval = 0x0000 
        bRefresh = 0x0000 
        bSynchAddress = 0x0000 

     Endpoint 1
        bLength = 0x0007 
        bDescriptorType = 0x0005 
        bEndpointAddress = 0x0081  <IN>
        bmAttributes = 0x0002  <BULK>
        wMaxPacketSize = 0x0200 
        bInterval = 0x0000 
        bRefresh = 0x0000 
        bSynchAddress = 0x0000 


Sending a ping with some debugging attached

	---Mike


-- 
-------------------
Mike Tancsa, tel +1 519 651 3400
Sentex Communications, mike at sentex.net
Providing Internet services since 1994 www.sentex.net
Cambridge, Ontario Canada   http://www.tancsa.com/