Re: Computone Intelliport II and Linux 9.0

From: Michael H. Warfield (mhw_at_wittsend.com)
Date: 06/08/04

  • Next message: Keith Duthie: "Re: [PATCH] Fix apm suspend with cs4231 based sound cards" 
    Date:	Tue, 8 Jun 2004 12:51:13 -0400
To: Sharon <sharon@sysman.co.za>, linux-kernel@vger.kernel.org

    Sharron,

            I hope you don't mind, but I've added the Linux Kernel developers
    list to the Cc on this list in a effort to get this patch integrated into
    the 2.4 kernel. The patch has been languishing for months, now, in
    spite of several requests to Marcello.

            I also just found out that I had been bounced (again) from the mail
    lists at vger (probably an outage at my MX server, again) so I had to
    resubscribe. I see from the archives that I missed a couple of Computone
    problem reports a while back, as well. All this same problem. :-(

    On Tue, Jun 08, 2004 at 01:19:50PM +0200, Sharon wrote:
    > Hi,
    > I am trying to get a PCI Computone Intellport II card working on Linux 9.0
    > (2.4.20-8).

            The lastest kernel for RedHat 9 is 2.4.20-31.9. I would
    strongly recommend upgrading. There are probably security issues
    that need to be addressed.

    > I use modprobe ip2 irq=0 io=1 and the board flashes green.

            First recommendation. Please do not set irq=0. That places
    that board (your first and, maybe, only board) in polling mode. Polling
    mode is not well tested, especially with PCI cards (io=1) and may
    have some timing problems over and above the known problem. I don't
    personally use it. It's really a hold over from old days when the
    IRQ subsystem in that driver didn't work very well (before I took over
    as maintainer and long before it was included in the kernel source tree).

    > When I insert the entries into /etc/inittab and execute init q.
    > I get Oops errors. ( if you need the exact error I will copy it for you)
    > Do you know if there is a patch that I can load to correct this error? If so
    > where do I get it from and how do I load it?

            Yes, there is a patch. I've sent it to Marcello several times
    now at several of his E-Mail addresses. I don't know if any of them
    are still good or if he's just so swamped that he hasn't been able to
    look at it. This is a known problem on fast CPU boards. I can go into
    a lot of technical details but the bottom line is that the problem has
    been known about for a long time. I've sent a patch to everyone reporting
    the problem and not a single person has reported any problem with the
    patch and several people reported that the Oops error was solved. The
    problem only occurs on fast CPUs (>400 MHz and aggravated by SMP)
    because of the speed of the CPU in relation to the speed of the processor
    on the Computone board itself creating a timing condition and busy board
    deadlock condition. The original fix for that problem is what's causing
    the Oopps on even faster CPU's.

            For some really strange reason, that I've never been able to
    ascertain, the Opps problem seems to show up on RedHat kernels but
    rarely (I've never seen it) on vanilla kernel.org kernels. What is
    the causal agent, there, that's aggravating the problem, I don't know.

            Since I haven't been able to catch Marcello's attention, in spite
    of my being the official maintainer of this driver, I'm spamming the kernel
    mailing list with the patch(s) in the faint hope of catching someone's
    attention.

            Attached to this message are two flavors of the patch for this
    problem. The patch "linux-2.4.22.diff" actually patches the RedHat
    2.4.20 kernel sources (all flavors) perfectly. I've checked it against
    2.4.20-30.9 and it patched cleanly with no fuzz or offsets. Please try
    that. Just cd into the kernel source directory and apply it with a
    "patch -p1 < .../linux-2.4.22.diff" and then rebuild your custom kernel.

            The other patch, patch-2.4.26ct.diff, is the diff against the
    2.4.26 kernel source tree. Will someone PLEASE integrate this into the
    sources or at least tell me why they can't? I've been requesting this
    since the 2.4.22 sources, and it still hasn't been integrated and I
    haven't heard a peep about why or why not. I can only assume that
    the direct E-Mail messages never got read.

    > I would also like to know how I can change the device names to be preceded
    > with 00. In other words I require that they get sorted as
    > F000,F001,F002,F003,F004 .. F010,F011 and not F0,F1,F10,F11
    > ...F2,F22,F23....etc because the device names are not sorted numerically
    > correctly with the physical positions on the 16 port Clusters.

            If you are not using devfs, you can do this with a simple shell
    script renaming the files in /dev/ttyF*. If you are using devfs, I would
    recommend strongly against it. With devfs, you would be better off
    creating symlinks from somewhere else. That being said, I usually
    advise against people "prettying things up" like this. In this particular
    case, it makes no difference, since the names are just strings (with
    devfs, they are actually in the source code, though). I've seen people
    make the mistake of doing this with IP addresses and getting royally
    burned when they discover that 010.000.000.001 != 10.0.0.1 and is really
    8.0.0.1 (010 is octal and equal to 8 decimal). It certainly shouldn't
    do any harm to rename the character device files in /dev to whatever
    convention you desire.

    > Thanks
    > Sharon

            Sorry for the problem. Let me know how the patch works out!

            Thanks!
            Mike 

    -- 
 Michael H. Warfield    |  (770) 985-6132   |  mhw@WittsEnd.com
  /\/\|=mhw=|\/\/       |  (678) 463-0932   |  http://www.wittsend.com/mhw/
  NIC whois:  MHW9      |  An optimist believes we live in the best of all
 PGP Key: 0xDF1DD471    |  possible worlds.  A pessimist is sure of it!

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