On Tue, 2021-01-05 at 12:30 +0000, Kai-Heng Feng wrote:
> On Tue, Jan 5, 2021 at 10:07 AM Pkshih <pkshih@realtek.com> wrote:
> >
> >
> > > -----Original Message-----
> > > From: Kai-Heng Feng [mailto:kai.heng.feng@canonical.com]
> > > Sent: Wednesday, December 30, 2020 11:53 AM
> > > To: Pkshih
> > > Cc: Larry.Finger@lwfinger.net; linux-wireless@vger.kernel.org; hugh.chao@c
> anonical.com;
> > > ethan.hsieh@canonical.com
> > > Subject: Re: 802.11ac AP mode support on Realtek 8821AE?
> > >
> > > On Wed, Dec 30, 2020 at 10:13 AM Pkshih <pkshih@realtek.com> wrote:
> > > >
> > > > On Fri, 2020-12-25 at 12:16 +0800, Kai-Heng Feng wrote:
> > > > > On Fri, Dec 25, 2020 at 2:18 AM Larry Finger <Larry.Finger@lwfinger.ne
> t>
> > > > > wrote:
> > > > > >
> > > > > > On 12/24/20 7:26 AM, Kai-Heng Feng wrote:
> > > > > > > Hi Ping-Ke,
> > > > > > >
> > > > > > > We've found that when creating 5G AP on 8821AE, it's not on other
> > > > > > > devices' wifi list.
> > > > > > >
> > > > > > > Here's the steps I used to create an AP:
> > > > > > > $ nmcli c add type wifi ifname wlp3s0 con-name hello autoconnect
> no ssid
> > > > > hello
> > > > > > > $ nmcli c modify hello 802-11-wireless.mode ap ipv4.method shared
> > > > > > > 802-11-wireless.band a
> > > > > > > $ nmcli connection up hello
> > > > > > >
> > > > > > > If we change "802-11-wireless.band" to "bg", then the AP can be
> > > > > > > scanned by other devices.
> > > > > > > Does 8821AE have hardware capability to support 5G AP?
> > > >
> > > > Yes, it has hardware capability of 5G AP.
> > > >
> > > > I want to make sure which chip you use. 8821AE with rtlwifi, or 8821CE
> with
> > > > rtw88?
> > >
> > > 8821AE with rtlwifi here.
> > >
> >
> > I'm not an expert in network-manager, so I try to bring up 5G softap with
> hostapd,
> > and then my cellphone can connect to it and ping ok.
> > Could you try it with attached hostapd configuration file?
> >
> > I use default configuration but change below
> > interface=wlan0
> > ssid=test-8821ae
> > hw_mode=a
> > channel=149
> >
> > The driver I use is built-in in kernel 5.9.10.
> > The hostap is hostap_2_9-1731-g56a1df71e (just list the version I use; I
> believe other version also work)
> 
> Using hostapd directly can make AP in 5G work. So apparently the issue
> lies between NetworkManager and WPA supplicant.
> However, though it works with hostapd, the signal strength is
> extremely weak. Is this expected?
> 

I found PHY and RF parameters are not updated properly years ago.
It would be much better if attached patch is applied. Please help to
try if it also works for you. 

side note: I don't submit this patch immediately, because I need
time to verify this patch before submitting.

---
Ping-Ke