How do I disable wifi power management?

Question

Level 1

8 points

How do I disable wifi power management?

I have constantly dropping wifi. I have done thorough examination of the problem and it comes down to the Apple driver not managing a poorly designed power management feature in a broadcom wireless chipset. Clicking "Renew DHCP Lease" works fine but is quite tedious. I want to disable the power management for the wifi so I can just avoid the chipset bugs directly.

I can write code so if you could point me to the interface for managing power to the chipset, that would be fine too.

Thank you for your time,

Dave

MacBook Pro, Mac OS X (10.6.8)

Posted on Jul 22, 2012 11:06 AM

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Answer 1

baltwo

Level 9

62,362 points

Jul 22, 2012 1:35 PM in response to secpro

Start with perusing the manpage for pmset. I do nothing wirelessly, so can't help with that.

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Answer 2

secpro Author

Level 1

8 points

Jul 22, 2012 2:59 PM in response to baltwo

pmset was already looked at but thank you for giving it a shot. 😉

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Answer 3

baltwo

Level 9

62,362 points

Jul 22, 2012 3:37 PM in response to secpro

Ah! The proverbial missing information. Then, I have nothing else to offer, except this: http://support.apple.com/kb/HT4628

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Answer 4

secpro Author

Level 1

8 points

Jul 22, 2012 7:52 PM in response to baltwo

I am trying to be positive here. I did not ask for standard troubleshooting steps for wifi. I asked a specific question about disabling power management for the wifi chipset. You took a wild guess that pmset would work and I thanked you for generosity at guessing. Your guess was wrong. I was willing to leave it at that.

I already know exactly what is wrong and what would fix it. I can fix it easily in Linux or in Windows. The fix is to disable power management for the chipset. This is easy to do on other operating systems. How is it done on OS X? Pmset was a good guess but it was not the right answer.

I still need a real answer. How do I disable power management on the wifi chipset? I am willing to modify a kext or otherwise pull out a hex editor if necessary.

Thanks

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Answer 5

etresoft

Level 8

46,104 points

Jul 22, 2012 8:34 PM in response to secpro

And you are going to hack up the kernel or change it with a hex editor? And you want someone here to give you pointers on where to do that? It sounds like you have all three traits of a great programmer. 🙂

I say start with CoreWLAN and System Configuration. I assume a working knowledge of COM and I/O Kit. If you don't have time for all of that, try 0xED.

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Answer 6

secpro Author

Level 1

8 points

Jul 22, 2012 8:45 PM in response to etresoft

I will hack it if necessary. 🙂 I would rather a more elegant solution were available but I have not seen any. I will take a peek at CoreWLAN to see if there are any PM functions in there. Thank you for something to look at. I will update if I find anything in there.

Ooo. That is a nice looking hex editor. Let's hope I do not need it.

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Answer 7

secpro Author

Level 1

8 points

Jul 22, 2012 8:51 PM in response to etresoft

Okay, in CoreWLAN, there is a function called setpower, probably not what I need but this looks like the right area. Much of it is available through the airport command but some of this stuff is not. This is looking interesting. Again, thank you.

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Answer 8

secpro Author

Level 1

8 points

Jul 22, 2012 9:09 PM in response to etresoft

Okay. None of what I need is in the public framework. Your answer was helpful but not useful. It was helpful in that it gave me more knowledge but useless in that there are no power management functions publicly exposed. It has given me an idea however. I will look for hidden interfaces within CoreWLAN and see if it is possible to manipulate it.

I really wish someone who knows the actual answer would respond. For all that is holy, it is incredibly easy to turn off PM for wifi in Linux and in Windows (iwconfig for linux and properties for windows). Why is it impossible in OS X?

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