Re: [PATCH] ath9k: turn on btcoex_enable as default

[Felix Fietkau]

On 2018-02-10 14:56, Kai Heng Feng wrote:
> 
>> On 9 Feb 2018, at 3:16 PM, Kalle Valo <kvalo@xxxxxxxxxxxxxx> wrote:
>> Sure, but we have to make sure that we don't create regressions on
>> existing systems. For example, did you test this with any system which
>> don't support btcoex? (just asking, haven't tested this myself)
> 
> No not really, but I will definitely test it.
> The only module I have that uses ath9k is Dellâs DW1707.
> How do I check if it support btcoex or not?
I just reviewed the code again, and I am sure that we cannot merge this
patch. Enabling the btcoex parameter makes the driver enable a whole
bunch of code starting timers, listening to some GPIOs, etc.

On non-btcoex systems, some of those GPIOs might be floating or even
connected to different things, which could cause a lot of undefined
behavior.

This is simply too big a risk, so there absolutely needs to be a
whitelist for systems that need this, otherwise it has to remain
disabled by default.

- Felix