RE: wifi: mt76: mt7915: fix broken background radar implementation

[<lukasz.michalski@onet.pl>]

Hi Felix, thanks for the info.

Is it only about mt7981 or mt7986 too?
Strange that patched code works flawlessly (or maybe firmware just sliently ignores scan requests?).

Lukasz Michalski

-----Original Message-----
From: Felix Fietkau <nbd@nbd.name> 
Sent: Tuesday, February 25, 2025 9:30 PM
To: lukasz.michalski@onet.pl; linux-wireless@vger.kernel.org; lorenzo@kernel.org
Subject: Re: wifi: mt76: mt7915: fix broken background radar implementation

Hi Lukasz,

On 21.02.25 16:35, lukasz.michalski@onet.pl wrote:
> Currently enabling background radar in hostapd results in unreachable AP.
> There is because of mistake in enabling background radar 
> implementation for
> mt7915 mcu driver - 3rd and 4th parameters are swapped.
> mt76_connac_mcu_rdd_cmd requires rx_sel as a fourth parameter but this 
> parameter is provided as third argument.
> Fix was tested on mt7981 and background radar works now correctly. 
> Other
> mt76 drivers do not have similar issues.
> The issue was also described here:
> https://github.com/openwrt/mt76/issues/958
> 
> Signed-off-by: Lukasz Michalski <lukasz.michalski@onet.pl>

MediaTek informed me that MT7981 does not actually have background radar detection in hardware, so this patch can't be merged.
We should instead change the driver code to refuse attempts to enable background radar detection on this chip.

- Felix