On Tue, Jul 26, 2016 at 12:34 PM, Chris Murphy <lists@colorremedies.com> wrote:
On Mon, Jul 25, 2016 at 12:07 PM, Rick Stevens <ricks@alldigital.com> wrote:
> On 07/23/2016 09:00 AM, Chris Murphy wrote:
>> On Fri, Jul 22, 2016 at 2:37 PM, Tod Merley <todbot88@gmail.com> wrote:
>>> .. so what mods are loaded to handle wifi and bluetooth ...
>>
>> 03:00.0 Network controller [0280]: Broadcom Corporation BCM4331
>> 802.11a/b/g/n [14e4:4331] (rev 02)
>>     Subsystem: Broadcom Corporation BCM4331 802.11a/b/g/n [14e4:4331]
>>     [...snip...]
>>     Kernel driver in use: bcma-pci-bridge
>>     Kernel modules: bcma
>>
>> lspci doesn't list Bluetooth. I'm not sure what driver is being  used,
>> but I suspect one of these:
>>
>> btusb                  45056  0
>> snd_hda_codec_hdmi     45056  1
>> btrtl                  16384  1 btusb
>> btbcm                  16384  1 btusb
>> btintel                16384  1 btusb
>> bluetooth             491520  36 bnep,hidp,btbcm,btrtl,btusb,rfcomm,btintel
>>
>> It looks like bluetooth module just drags in generic, Intel, Broadcom,
>> and Realtek device drivers, whether the hardware is present or not.
>>
>> I was almost ready to give up on b43/bcma because I don't get even get
>> 802.11n support with that driver. What I found on Broadcom's site for
>> Linux is hybrid-v35_64-nodebug-pcoem-6_30_223_271.tar.gz but I haven't
>> gone down that rabbit hole yet.
>
> Try doing googling for this issue. I looked and the bcma driver doesn't
> have a bluetooth co-exist flag like the iwlwifi does. I was going to
> suggest making sure that was on, but since I don't see that option it'd
> be useless.
>
> According to Broadcom:
>
> Do Bluetooth wireless technology and IEEE 802.11 interfere with each other?
>
> Bluetooth wireless technology and 802.11b/g both use the 2.4 GHz ISM
> (Industrial, Scientific, Medical) unlicensed spectrum, and in some
> configurations can interfere with each other. If the Bluetooth and
> 802.11b/g antennas are more than 3 meters apart, however, interface in
> minimal. Co-existence schemes such as adaptive frequency hopping have
> been implemented to address potential interference issues and Broadcom
> has introduced its InConcert® coexistence technology, which mitigates
> interference problems.
>
> Hmmm. Apparently not in your case. Sorry.


My guess is Apple's drivers for macOS and Windows do this adaptive
hopping, and the open source drivers do not. Or at least, they can
still conflict some of the time or in a manner that just causes
bluetooth devices to get dropped and not recover until the wifi radio
is turned off.

With a laptop the two most common use-cases are "mobile" where you are
working unplugged/mobile with the laptops's keyboard and pointing device, and
more stationary situations where you are plugged in to mains and may have
access to a network jack, so many users won't need wifi and bluetooth at the
same time.  Where I work, there is no wifi but iMacs are purchased with
bluetooth mouse and keyboard.  With a bunch of systems in a cubicle farm,
bluetooth is not reliable, so users switch to USB mouse and keyboard.

 

But there are other problems with the b43 situation where it just
doesn't get much dev attention anymore, and for Pete's sake I'm stuck
on 802.11g, not even n is possible with b43.


--
Chris Murphy



--
George N. White III <aa056@chebucto.ns.ca>
Head of St. Margarets Bay, Nova Scotia