RE: [PATCH] wifi: rtw89: retry efuse physical map dump on transient failure

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

Christian Hewitt <christianshewitt@gmail.com> wrote:
> > On 2 Mar 2026, at 9:47 am, Ping-Ke Shih <pkshih@realtek.com> wrote:
> >
> > Christian Hewitt <christianshewitt@gmail.com> wrote:
> >> On Radxa Rock 5B with a RTL8852BE combo WiFi/BT card, the efuse
> >> physical map dump intermittently fails with -EBUSY during probe.
> >> The failure occurs in rtw89_dump_physical_efuse_map_ddv() where
> >> read_poll_timeout_atomic() times out waiting for the B_AX_EF_RDY
> >> bit after 1 second.
> >
> > I'm checking internally how we handle this case.
> >
> > [...]
> >
> >>
> >> For context, firmware also fails (and recovers) sometimes:
> >
> > Did you mean this doesn't always happen? sometimes?
> 
> It’s another intermittent behaviour observed on this board (and not
> related to the issue this patch targets). It occurs less frequently
> than the efuse issue and the existing retry mechanism in the driver
> ensures firmware load always succeeds.

As intermittent behaviour, it might be not worth to try DMA. 

Recently, we have some patches related to PCI hardware settings. Please
use the latest driver including patch [1] to see if it can be stable.

[1] af1e82232b98 ("wifi: rtw89: pci: restore LDO setting after device resume")

> 
> > We has seen similar log because of 36-bit DMA. Try below to force 32- or 36-
> > bit DMA to see if it can resolve problem in your platform.
> 
> I can experiment but this doesn’t happen often so I probably can’t
> provide meaningful feedback.