Luca Coelho [off-list ref] writes:

On Mon, 2013-10-28 at 23:39 +0000, Ben Hutchings wrote:

quoted

On Sat, 2013-10-26 at 22:34 +0200, Pali Rohár wrote:

quoted

From: David Gnedt <redacted>

Port the bt_coex_mode sysfs interface from wl1251 driver version included
in the Maemo Fremantle kernel to allow bt-coexistence mode configuration.
This enables userspace applications to set one of the modes
WL1251_BT_COEX_OFF, WL1251_BT_COEX_ENABLE and WL1251_BT_COEX_MONOAUDIO.
The default mode is WL1251_BT_COEX_OFF.
It should be noted that this driver always enabled bt-coexistence before
and enabled bt-coexistence directly affects the receiving performance,
rendering it unusable in some low-signal situations. Especially monitor
mode is affected very badly with bt-coexistence enabled.

[...]

This should be implemented consistently with other drivers:

drivers/net/wireless/ath/ath9k/htc_drv_init.c:module_param_named(btcoex_enable, ath9k_htc_btcoex_enable, int, 0444);
drivers/net/wireless/ath/ath9k/init.c:module_param_named(btcoex_enable, ath9k_btcoex_enable, int, 0444);
drivers/net/wireless/b43/main.c:module_param_named(btcoex, modparam_btcoex, int, 0444);
drivers/net/wireless/ipw2x00/ipw2200.c:module_param(bt_coexist, int, 0444);
drivers/net/wireless/iwlegacy/common.c:module_param(bt_coex_active, bool, S_IRUGO);
drivers/net/wireless/iwlwifi/iwl-drv.c:module_param_named(bt_coex_active, iwlwifi_mod_params.bt_coex_active,
drivers/net/wireless/ti/wlcore/sysfs.c:static DEVICE_ATTR(bt_coex_state, S_IRUGO | S_IWUSR,

Oh, hmm, I see a problem here.

With so many drivers doing the same thing, isn't it about time to add
this to nl80211?

Yes, this really needs to be in nl80211. I even suggested this years ago
but was turned down at the time. Can't remember the reason anymore.

-- 
Kalle Valo