USB device driver questions - Linux

This is a discussion on USB device driver questions - Linux ; I'm working on a couple of device drivers for some USB devices (X10's CM15A, CM19A and Insteon's PLC). They've been working well (enough) until about Kernel 2.6.15. I've made the changes for the MODULE_PARM to module_param (I think that the ...

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Thread: USB device driver questions

  1. USB device driver questions

    I'm working on a couple of device drivers for some USB devices (X10's
    CM15A, CM19A and Insteon's PLC). They've been working well (enough)
    until about Kernel 2.6.15. I've made the changes for the MODULE_PARM
    to module_param (I think that the spelling) but I'm now running into
    read errors in my interrupt_in_callback. This is over my head and I
    need to fix this. Where is a good place to start? I know it won't be
    fixed immediately. I'm not looking for someone else to fix this just
    the pointers to where I can learn to fix this.

    Thanks.

    PS, yes I googled and most of it is the older device driver stuff from
    2004 and earlier.

    --
    Linux Home Automation Neil Cherry ncherry@linuxha.com
    http://www.linuxha.com/ Main site
    http://linuxha.blogspot.com/ My HA Blog
    http://home.comcast.net/~ncherry/ Backup site

  2. Re: USB device driver questions

    On Mon, 03 Jul 2006 18:18:46 -0500, Neil Cherry wrote:

    > [...] They've been working well (enough)
    > until about Kernel 2.6.15. [...] I'm now running into
    > read errors in my interrupt_in_callback.


    OK, so it worked before, and does not work now. Ergo, a change in
    the stack broke it. So, what could it be? There weren't any API
    changes or core changes. It must be an update to the HCD. Right?

    What's the urb->status? Maybe it's the schedule budgeting problem.

    -- Pete


  3. Re: USB device driver questions

    On Thu, 06 Jul 2006 23:02:22 -0700, Pete Zaitcev wrote:
    > On Mon, 03 Jul 2006 18:18:46 -0500, Neil Cherry wrote:
    >
    >> [...] They've been working well (enough)
    >> until about Kernel 2.6.15. [...] I'm now running into
    >> read errors in my interrupt_in_callback.

    >
    > OK, so it worked before, and does not work now. Ergo, a change in
    > the stack broke it. So, what could it be? There weren't any API
    > changes or core changes. It must be an update to the HCD. Right?
    >
    > What's the urb->status? Maybe it's the schedule budgeting problem.


    I'm afraid that the read errors in my interrupt_in_callback are
    due to the fact that I wrote my debug strings to the usb device
    instead of the tty (I sent the information to the wrong fd, argh!)
    Sorry for the false alarm, it is again working properly.

    This does seem to indicate that I may have a problem with sending data
    to the USB device. I have no flow control built into the driver. If
    the app sends too much the driver attempts to write too much. I
    decided to keep the driver simple but may work on that in the future.

    Thanks!

    --
    Linux Home Automation Neil Cherry ncherry@linuxha.com
    http://www.linuxha.com/ Main site
    http://linuxha.blogspot.com/ My HA Blog
    http://home.comcast.net/~ncherry/ Backup site

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