Re: [PATCH rtw-next 0/5] wifi: rtw88: pci: Support an older design, like RTL8821AE/RTL8812AE

["Luka Gejak" <luka.gejak@linux.dev>]

Hi Ping-Ke,

October 27, 2026 at 2:52 AM, "Ping-Ke Shih" <pkshih@realtek.com> wrote:


> 
> Bitterblue Smith <rtl8821cerfe2@gmail.com> wrote:
> 
> > 
> > This series extends rtw88_pci to support an older design, like
> >  RTL8821AE, RTL8812AE, RTL8723BE, etc.
> > 
> The older design is own-bit ring, and the new is read/write index ring
> with buffer descriptor. Can we use 'own-bit' instead of 'old' as the file
> name ?

I agree with this name proposition.

> 
> > 
> > After this, another ~20 small patches can enable support for RTL8821AE
> >  and RTL8812AE.
> > 
> Will you plan to implement RTL8723BE (you listed it above) in rtw88?
> 

As far as I know Bitterblue hasn't commited to implementing RTL8723BE
in rtw88. That development is being done by WillyHB on github. This
series is requirement for future implementation of RTL8723BE in rtw88.

> > 
> > Then rtl8821ae can be deleted from rtlwifi.
> > 
> Luka asked me to merge AP mode for RTL8723BS, because the AP mode of staging
> rtl8723bs can work well. If you decide to delete it from rtlwifi, please
> make sure all features are implemented before deleting. However, I can't
> say what the exactly all features are. 
> 
> [1] https://lore.kernel.org/linux-wireless/d6af5cebfa1a46e2bc2da662634766d7@realtek.com/T/#maa2a3e897d5d488d0219399f9555d88b9ef6504f
> 
> > 
> > rtw88 is not without problems, but in my experience it's more reliable
> >  with these two chips. In the 6-8 months I used this code, I observed
> >  these problems with rtw88:
> >  
> >  * The top speed is a bit lower: ~220 Mbps instead of ~300 Mbps. In the
> >  case of TX, the difference is due to the EDCA parameters. rtw88 uses
> >  the ones from mac80211 (rtw_conf_tx()), whereas rtlwifi uses its own
> >  "turbo" values when there are not too many non-BE packets
> >  (rtl8821ae_dm_check_edca_turbo()). Not sure why the RX speed is
> >  lower.
> > 
> Maybe you can try to compare them by VO or VI packets?
> 
> > 
> > * RTL8821AE RX speed gets limited to 70-100 Mbps sometimes. If I watch
> >  a Youtube video with Bluetooth headphones for 10 minutes and then
> >  switch to another wifi adapter while the video is playing, leaving
> >  the RTL8821AE's wifi side idle, usually within 20 minutes it will
> >  start to raise IMR_RDU when it reaches the end of the RX ring and
> >  goes back to the beginning.
> > 
> Does it still happen without Bluetooth? IIRC the rtw88 BT-coexistence 
> mainly supports RTL8822BE and RTL8822CE. I believe the algorithm can
> share with other chips, but control registers or additional settings might
> be missing.
> 
> > 
> > It uses RX descriptor number 511, then number 0, then it doesn't
> >  want to use number 1 for "a while". It raises IMR_RDU once or twice,
> >  and only then it moves on to number 1, 2...
> >  
> >  Usually when it raises IMR_RDU there are 510 or 511 RX descriptors
> >  available (out of 512), so it has no excuse.
> >  
> >  Once it has raised IMR_RDU the RX speed doesn't exceed 70-100 Mbps
> >  anymore.
> > 
> If driver can receive packets on time, how does it raise ISR_RDU? 
> Is RX interrupt triggered on time?
> 
> > 
> > Powering off and on again, which happens a lot when the wifi
> >  interface is idle, doesn't help.
> >  
> >  The only thing that seems to help is reloading the driver, but even
> >  that may not always work.
> > 
> I think reloading the driver and interface idle are very similar (almost
> the same). No idea why they have different results. 

Maybe firmware reload?

> 
> > 
> > Switching to another wifi adapter while playing some video is the
> >  most reliable way to trigger the problem, but it can also happen
> >  randomly, it just takes many hours.
> > 
> Thanks for your effort. 
> 
> Ping-Ke
>

Best regards,
Luka Gejak