1394 - Set Speed For Async Read/Write/Lock

Discussion in 'Windows Vista Drivers' started by Udo Reuther, Dec 8, 2003.

  1. Udo Reuther

    Udo Reuther Guest

    Hello,

    is it possible to set the speed for a 1394 read/write/lock
    request?
    I'm encountering the problem that I can't access a device
    with an 1394B PHY and an older only S400 capable Link
    chip. Thus the PHY reports "I can handle S800 requests"
    with its Self Id Packets (which is correct): Packets
    between other nodes connected to this node can be S800.
    This makes sense.
    But the Link says "I can only up to S400" in the Bus Info
    Block. So I would expect the Windows 1394 driver to send
    S400 packets to the node. It doesn't. I sends S800 packets.

    So, again: Can I set the speed? How? And just for
    curiousity: Is MS doing wrong or is the device beyond the
    standard?

    Udo.
     
    Udo Reuther, Dec 8, 2003
    #1
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  2. Udo Reuther

    Raj Guest

    Windows doesnot support 1394b in 2000 or XP.
    Microsoft plans to support 1394b in next OS Longhorn.

    We also observed this problem.
     
    Raj, Dec 9, 2003
    #2
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  3. Block. So I would expect the Windows 1394 driver to send
    Looks like a bug, the 1394 stack must consult the Speed Map matrix to set the
    request speed.
    Try AsyncRead.nSpeed and such.
     
    Maxim S. Shatskih, Dec 11, 2003
    #3
  4. Udo Reuther

    Ricky Sticky Guest

    Actually, we've found that XP SP 1 supports 1394b quite well.

    --ricky
     
    Ricky Sticky, Dec 12, 2003
    #4
  5. Udo Reuther

    Raj Guest

    Actually, we've found that XP SP 1 supports 1394b quite well.

    Can you expand on that please. I talked to Microsoft programmers. They
    said 1394b is not suppported in XP or 2000. I was told that I have to
    wait for Longhorn. Is it that some feautures of 1394b are supported in
    XP SP1.
    May be it is happening without their intentional design!!

    1) Are you suggesting we can send Async packets of 4096 can be sent at
    S800 if we use XP SP1.

    2) How should speed field be for XP SP1 APIs.

    3) Will Isoch bandwidth units be reported as more than what we get at
    S400. Is bandwidth units nearly 8000. Can I send Isoch packets of
    4096*2 bytes with XP SP1.

    Thanks.
     
    Raj, Dec 15, 2003
    #5
  6. Udo Reuther

    Ricky Sticky Guest

    Can you expand on that please. I talked to Microsoft programmers. They
    Possibly. We just started trying some stuff and things pretty
    much work.
    I haven't tested maximum packet size, but all our asynch communication
    runs at S800 without problems.
    Not sure. We haven't modified our software and I'm a hardware
    guy.
    Yes, you can send big packets and they arrive without problems.

    --ricky
     
    Ricky Sticky, Dec 30, 2003
    #6
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