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Thread: BCM4321 failure on upgrade to 11.10

  1. #11
    Join Date
    Nov 2011
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    21

    Re: BCM4321 failure on upgrade to 11.10

    Quote Originally Posted by KapitaenM View Post
    Hopefully b43 can make usable the 4329 chipset in DMA, because it's slow in PIO.
    KapitaenM, uh, oh, I certainly hope that's not the case -- I bought the router and card because of their speed. And I found that things worked just fine when using the x86_64 10.04.

  2. #12
    Join Date
    Nov 2011
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    21

    Re: BCM4321 failure on upgrade to 11.10

    Quote Originally Posted by KapitaenM View Post
    I've only got mine working via PIO mode. You can try it out with rmmod b43; modprobe b43 pio=1
    Thanks KapitaenM, this does at least allow me to connect, though at a severe performance penalty. I get less than 25% of normal download speeds.

    Sigh. Under "Known Issues" for the b43 driver (http://wireless.kernel.org/en/users/Drivers/b43), I see
    BCM4321: some cards do not work in DMA mode (PIO is needed).
    I don't understand the difference between DMA and PIO. Is DMA the "normal" or "high-speed" mode of the card, and PIO the "legacy" slowed-down speed?

  3. #13
    Join Date
    Jun 2009
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    2

    Re: BCM4321 failure on upgrade to 11.10

    The difference is we don't get direct memory access (DMA), so a lot more CPU is used.

    But yes, programmed input/output is pretty old, albeit easier to implement. DMA support is supposedly in progress, from what I researched.

    Other than that, the alternative is going back to 2.6.36 or sooner, and using broadcom-wl.
    Last edited by KapitaenM; December 7th, 2011 at 07:24 PM.

  4. #14
    Join Date
    Feb 2006
    Beans
    5
    Distro
    Ubuntu Breezy 5.10

    Re: BCM4321 failure on upgrade to 11.10

    Quote Originally Posted by gopo View Post
    That is interesting! Have you tried either of these drivers on an i386 machine?
    Yes as written in my first post, the card is working fine on i386, but I cannot use my 6GB of RAM in this case

  5. #15
    Join Date
    Oct 2009
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    14

    Re: BCM4321 failure on upgrade to 11.10

    So I am glad I finally found this post I have been looking for one since 10.10 that is when my card stop working. I had found lots of post related to other bcm43 chips but none specifically for 4321. So KapitaneM the work around you gave here
    Code:
    rmmod b43; modprobe b43 pio=1 qos=0
    worked for me. I didn't try the first one. I agree with gopo though my card now says it is only 11 Mb/s. None the less at least I can stop using my phone as my wireless connection having it plugged in all the time has destroyed the battery.

    Does anyone know why the wl module isn't working though? I tried both the Ubuntu build and building it myself off Broadcom's website. I am actually talking with Broadcom's tech support right now via email though they don't seem very helpful. Has a bug been filed somewhere?

    Thanks again KapitaneM

  6. #16
    Join Date
    Oct 2009
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    14

    Re: BCM4321 failure on upgrade to 11.10

    Well after a few hours of using my connection cuts in and out every once in a while. I guess I will just live with it for the time being.
    I also wanted to point out I had to create a b43.conf file afterwards to make sure the module was loaded with the correct options. See this thread
    http://ubuntuforums.org/showthread.php?t=1266620

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