[fedora-arm] wlan0 de-activated?

[Clive Messer]

On Mon, 2015-03-02 at 17:50 +1100, Robert Brown wrote:

> Yes I have found this to be the case. What is also interesting is that 
> there is also a power issue as Peter pointed out. I find that if I leave 
> the hdmi monitor powered on there must be some extra voltage support to 
> the bus because the USB wirless device stays up. When I power down the 
> monitor I lose the wireless device within a few minutes.

I have a whole list of "cranky" when it comes to wi-fi dongles. I have
spent too many hours with a scope and one specific piece of hardware
trying to "debug" the over/undershoot with the way they have implemented
cascading "buck" regs.... Which I suspect may also be the case with your
hardware, resulting in what happens when you power down the monitor and
that affecting wi-fi stability.

> Thanks for the suggestion. My solution is going to be to get the 
> on-board device sorted using the rtl8188eu module to avoid the USB 
> device power issue. So I have grabbed the source files from git and am 
> engrossed in the joys of compiling.

I'm have zero experience with the EU variant part. Think this uses a
separate driver, rather than the "stock" 8188/8192 drivers. I'm more
than familiar with the 8188CUS and 8192CU having purchased several
hundred for commercial projects. One of the first things I do after
every Fedora release kernel push, is rebuild with the mainline rtl8192cu
driver patched-out and the Realtek VENDOR 8188/8192 driver, patched-in.

http://www.squeezecommunity.org/repo/21/SRPMS/kernel-3.18.7-200.1.fc21.src.rpm

I had a little chuckle when the Pi guys pushed their 3.18 device tree
kernel to stable, having forgotten to patch-in the VENDOR 8188 driver,
which they had been using by default with older kernels for quite some
time, and the squealing from users with wi-fi issues started. The 8188
being their "officially unofficial" dongle of choice for Pi hardware.
(The Pi people see to prefer the Edimax EW-7811UN part which uses the
Realtek 8188CUS chipset.)

I'm getting my fingers burned right now, having made an akmod package to
support the people using the Pi2B images and Ralink MT7601U dongles.
There appears to be a whole load of crankiness with this Ralink
(Mediatek) supplied driver and there isn't an upstream driver. LOL.

I hate wi-fi!

Regards

Clive
-- 
Clive Messer <clive.m.messer at gmail.com>