AP mode on RTW88 8821cs

AP mode on RTW88 8821cs

[Konstantin Kletschke]

We have a rockchip rk3328 board with an 8821cs chip connected via SDIO.
Well, cs impiles SDIO, cu is USB variant.

Normally thinks work quite well for use but we do not get AP mode to
work.
We use 6.5.13 kernel with our customized DT and the in kernel 8821cs
driver:

rtw88_8821cs           12288  0
onboard_usb_hub        12288  0
rtw88_8821c            81920  1 rtw88_8821cs
crct10dif_ce           12288  1
rtw88_sdio             24576  1 rtw88_8821cs
rtw88_core            167936  2 rtw88_8821c,rtw88_sdio
mac80211              929792  2 rtw88_sdio,rtw88_core
libarc4                12288  1 mac80211
cfg80211              921600  2 rtw88_core,mac80211

We tried with wpa_cli and hostapd but to no avail.
I tried hostapd with wlan0 and eth0 bridged into br0, the SSID appears
in the wlan search results in other devices, connectig _seems_ to work
but getting an IP is not possible.

What my colleauge and me especially noticed, the TX counter for the
wlan0 interface in this use case runs, RX stays at 0:

br0       Link encap:Ethernet  HWaddr 4A:86:7D:63:5C:59
          inet addr:10.16.10.103  Bcast:10.16.255.255  Mask:255.255.0.0
          inet6 addr: fe80::4886:7dff:fe63:5c59/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:111361 errors:0 dropped:3479 overruns:0 frame:0
          TX packets:28144 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:13333769 (12.7 MiB)  TX bytes:3847859 (3.6 MiB)

eth0      Link encap:Ethernet  HWaddr 86:E0:C0:EA:FA:A8
          inet6 addr: fe80::84e0:c0ff:feea:faa8/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:112803 errors:0 dropped:219 overruns:0 frame:0
          TX packets:28405 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:15102222 (14.4 MiB)  TX bytes:3891727 (3.7 MiB)
          Interrupt:51

wlan0     Link encap:Ethernet  HWaddr F0:B0:40:4F:70:BC
          inet6 addr: fe80::f2b0:40ff:fe4f:70bc/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:123446 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:18783966 (17.9 MiB)

In order to provide useful debug information, what should I look into?

Is it a known issue or should AP mode work flawlessly with those
drivers, which implies I forgot something.
When I use my software with an external USB WLAN stick with another
driver, exchange all wlan0 by wlan1 occurences only:

rtl8xxxu              192512  0
rtl8192cu              81920  0
rtl_usb                16384  1 rtl8192cu
rtl8192c_common        65536  1 rtl8192cu
rtlwifi               118784  3 rtl8192c_common,rtl_usb,rtl8192cu

the software AP works immediately.

Kind Regards
Konstantin


-- 
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Konstantin Kletschke
Berenbosteler Straße 76 B
30823 Garbsen

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konstantin.kletschke@inside-m2m.de
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RE: AP mode on RTW88 8821cs

[Ping-Ke Shih]

> -----Original Message-----
> From: Konstantin Kletschke <konstantin.kletschke@inside-m2m.de>
> Sent: Thursday, March 21, 2024 6:56 PM
> To: linux-wireless@vger.kernel.org
> Subject: AP mode on RTW88 8821cs
> 
> We have a rockchip rk3328 board with an 8821cs chip connected via SDIO.
> Well, cs impiles SDIO, cu is USB variant.
> 
> Normally thinks work quite well for use but we do not get AP mode to
> work.
> We use 6.5.13 kernel with our customized DT and the in kernel 8821cs
> driver:
> 
> rtw88_8821cs           12288  0
> onboard_usb_hub        12288  0
> rtw88_8821c            81920  1 rtw88_8821cs
> crct10dif_ce           12288  1
> rtw88_sdio             24576  1 rtw88_8821cs
> rtw88_core            167936  2 rtw88_8821c,rtw88_sdio
> mac80211              929792  2 rtw88_sdio,rtw88_core
> libarc4                12288  1 mac80211
> cfg80211              921600  2 rtw88_core,mac80211
> 
> We tried with wpa_cli and hostapd but to no avail.
> I tried hostapd with wlan0 and eth0 bridged into br0, the SSID appears
> in the wlan search results in other devices, connectig _seems_ to work
> but getting an IP is not possible.
> 
> What my colleauge and me especially noticed, the TX counter for the
> wlan0 interface in this use case runs, RX stays at 0:
> 
> br0       Link encap:Ethernet  HWaddr 4A:86:7D:63:5C:59
>           inet addr:10.16.10.103  Bcast:10.16.255.255  Mask:255.255.0.0
>           inet6 addr: fe80::4886:7dff:fe63:5c59/64 Scope:Link
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:111361 errors:0 dropped:3479 overruns:0 frame:0
>           TX packets:28144 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:1000
>           RX bytes:13333769 (12.7 MiB)  TX bytes:3847859 (3.6 MiB)
> 
> eth0      Link encap:Ethernet  HWaddr 86:E0:C0:EA:FA:A8
>           inet6 addr: fe80::84e0:c0ff:feea:faa8/64 Scope:Link
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:112803 errors:0 dropped:219 overruns:0 frame:0
>           TX packets:28405 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:1000
>           RX bytes:15102222 (14.4 MiB)  TX bytes:3891727 (3.7 MiB)
>           Interrupt:51
> 
> wlan0     Link encap:Ethernet  HWaddr F0:B0:40:4F:70:BC
>           inet6 addr: fe80::f2b0:40ff:fe4f:70bc/64 Scope:Link
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:0 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:123446 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:1000
>           RX bytes:0 (0.0 B)  TX bytes:18783966 (17.9 MiB)
> 
> In order to provide useful debug information, what should I look into?
> 
> Is it a known issue or should AP mode work flawlessly with those
> drivers, which implies I forgot something.
> When I use my software with an external USB WLAN stick with another
> driver, exchange all wlan0 by wlan1 occurences only:
> 
> rtl8xxxu              192512  0
> rtl8192cu              81920  0
> rtl_usb                16384  1 rtl8192cu
> rtl8192c_common        65536  1 rtl8192cu
> rtlwifi               118784  3 rtl8192c_common,rtl_usb,rtl8192cu
> 
> the software AP works immediately.
> 

We had similar discussion before [1]. I think Martin will take his time to
investigate how to enable AP mode on SDIO WiFi cards.

[1] https://lore.kernel.org/linux-wireless/36972ff5-0c48-4bd2-8f9a-9649bfa24225@lexina.in/

Re: AP mode on RTW88 8821cs

[Konstantin Kletschke]

Dear Ping-Ke,

On Fri, Mar 22, 2024 at 12:16:14AM +0000, Ping-Ke Shih wrote:

> We had similar discussion before [1]. I think Martin will take his time to
> investigate how to enable AP mode on SDIO WiFi cards.
> 
> [1] https://lore.kernel.org/linux-wireless/36972ff5-0c48-4bd2-8f9a-9649bfa24225@lexina.in/

many thanks for letting me now, I did not find this with my google fu
initially so I am aware now this is known.

If there is anything I could provide, anybody let me know. 
We have the hardware and compiler(s) :-)

Regards
Konstantin

Re: AP mode on RTW88 8821cs

[Kalle Valo]

Ping-Ke Shih <pkshih@realtek.com> writes:

> We had similar discussion before [1]. I think Martin will take his time to
> investigate how to enable AP mode on SDIO WiFi cards.
>
> [1] https://lore.kernel.org/linux-wireless/36972ff5-0c48-4bd2-8f9a-9649bfa24225@lexina.in/

If AP mode is broken on SDIO devices it would be user friendly to
disable AP mode support (NL80211_IFTYPE_AP in wiphy->interface_modes) on
SDIO until the issues are fixed. In other words, the driver should only
enable features which work reliably.

-- 
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

Re: AP mode on RTW88 8821cs

[Ping-Ke Shih]

On Fri, 2024-03-22 at 17:36 +0200, Kalle Valo wrote:
> 
> Ping-Ke Shih <pkshih@realtek.com> writes:
> 
> > We had similar discussion before [1]. I think Martin will take his time to
> > investigate how to enable AP mode on SDIO WiFi cards.
> > 
> > [1] https://lore.kernel.org/linux-wireless/36972ff5-0c48-4bd2-8f9a-9649bfa24225@lexina.in/
> 
> If AP mode is broken on SDIO devices it would be user friendly to
> disable AP mode support (NL80211_IFTYPE_AP in wiphy->interface_modes) on
> SDIO until the issues are fixed. In other words, the driver should only
> enable features which work reliably.
> 

I made a patch [1] to set station mode only for SDIO devices. Meanwhile,
I would like to remove mesh point support from rtw88 because I don't have
impression that it can work and someone uses that. Otherwise, when SDIO
devices can support AP mode, we need another patch to declare "SDIO
doesn't support mesh point", but actually no chip can support that feature. 

[1] https://lore.kernel.org/linux-wireless/20240326014707.17458-1-pkshih@realtek.com/T/#u

Re: AP mode on RTW88 8821cs

[Kalle Valo]

Ping-Ke Shih <pkshih@realtek.com> writes:

> On Fri, 2024-03-22 at 17:36 +0200, Kalle Valo wrote:
>> 
>> Ping-Ke Shih <pkshih@realtek.com> writes:
>> 
>> > We had similar discussion before [1]. I think Martin will take his time to
>> > investigate how to enable AP mode on SDIO WiFi cards.
>> > 
>> > [1]
>> > https://lore.kernel.org/linux-wireless/36972ff5-0c48-4bd2-8f9a-9649bfa24225@lexina.in/
>> 
>> If AP mode is broken on SDIO devices it would be user friendly to
>> disable AP mode support (NL80211_IFTYPE_AP in wiphy->interface_modes) on
>> SDIO until the issues are fixed. In other words, the driver should only
>> enable features which work reliably.
>> 
>
> I made a patch [1] to set station mode only for SDIO devices.

Very nice, thanks Ping.

> Meanwhile, I would like to remove mesh point support from rtw88
> because I don't have impression that it can work and someone uses
> that.

Yeah, if you are not 100% sure that mesh works then it's better to
remove it from rtw88. If out of some miracle the mesh mode would
actually work, I'm sure someone will then report that to us and we can
add it back to rtw88.