RE: [PATCH v2 2/2] rtw88: add a debugfs entry to enable/disable coex mechanism

Kalle Valo [off-list ref] :

[off-list ref] writes:

quoted

From: Yan-Hsuan Chuang <redacted>

Sometimes we need to stop the coex mechanism to debug, so that we
can manually control the device through various outer commands.
Hence, add a new debugfs coex_enable to allow us to enable/disable
the coex mechanism when driver is running.

To disable coex
echo 0 > /sys/kernel/debug/ieee80211/phyX/rtw88/coex_enable

To enable coex
echo 1 > /sys/kernel/debug/ieee80211/phyX/rtw88/coex_enable

To check coex dm is enabled or not
cat /sys/kernel/debug/ieee80211/phyX/rtw88/coex_enable

I forgot, did we add a command to nl80211 for managing btcoex? At least
we have talking about that for years. Please check that first before
adding a debugfs interface for this.

Yes, I found there was a thread [1] talking about adding a callback to
enable/disable btcoex, but it seems not get applied eventually.

And there's another thread [2] talking about add a btcoex subsystem.
But seems like nobody can implement it cleanly in the host.

I think adding btcoex subsystem could have a lot of pain since each
vendor is using different mechanism controlling the btcoex, and it
usually comes with RF related design which is difficult to write a common
function to deal with all kinds of them.

Yen-Hsuan

[1] https://patchwork.kernel.org/patch/10252135/
[2] https://www.spinics.net/lists/linux-wireless/msg133333.html