RE: [PATCH] rtw88: add TX power limit support to 114 and 130 channels

[Ping-Ke Shih <pkshih@realtek.com>]

Thadeu Lima de Souza Cascardo <cascardo@igalia.com> wrote:
> On Fri, Apr 10, 2026 at 03:56:11AM +0000, Ping-Ke Shih wrote:
> > Thadeu Lima de Souza Cascardo <cascardo@igalia.com> wrote:
> > > Though 114 and 130 are not usual channels, they are found in the wild with
> > > setups using 5350MHz as the center frequency of a 80MHz setup.
> >
> > What did the AP setup? channel 114 160MHz?
> > I wonder why rtw88 can select a not usual channel 114 80MHz.
> >
> > Please share your environment setup.
> >
> 
> This is a Mikrotik that uses channel 130 at 80MHz.

I'm surprised that an AP can work on this not usual channel/bandwidth. 
Can you change the setting to usual channel/bandwidth? We'd avoid using
this unsupported channel/bandwidth by [1].

> 
> > >
> > > rtw88 supports that, but issues a WARNING because it cannot find the TX
> > > power limit for those channels.
> >
> > Actually, rtw88 hardware can't support that, so we are working on patch
> > to avoid selecting unusual channels. Can it work properly with
> > the AP after this patch?
> >
> 
> It does work just fine even without the patch. The only issue is the
> WARNING that is triggered.
> 

As internal discussion, hardware doesn't work on channel 130 80M,
which means connection might be well, but it can't yield expected performance.
More, the power limit is not really verified on ch130 80M, so we wonder
that the signal might not in expectation.

By above reasons, we'd avoid using channel 114 and 130.

[1] https://lore.kernel.org/linux-wireless/20260413053601.13037-1-pkshih@realtek.com/T/#u