Re: brcmfmac disconnects when iwd scans

On Wed, May 7, 2025 at 9:27 AM Arend van Spriel
<[email protected]> wrote:
>
> On 5/7/2025 3:54 PM, KeithG wrote:
> > further information...
> >
> > I tried this with 2 different pi4s and have been able to confirm
> > wpa_supplicant/hostapd is stable on the Pi4 (will try others when I
> > get a chance). I also tried both the 'shipping' brcmfmac43455 firmware
> > and the 'latest'. It is only with the 'latest' that I get reliable
> > connections. With the 'shipping' version, I can get connections for
> > both wlan0 with wpa_suppolicant and ap0 with hostapd, but the ap0
> > connection is flaky without any connection on wlan0. And I cannot
> > sustain both connections at all. This 'latest' firmware is required
> > for a sustainable, reliable ap0 with connection with hostapd.
> >
> > this is the firmware required:
> > [    3.658201] brcmfmac: brcmf_fw_alloc_request: using
> > brcm/brcmfmac43455-sdio for chip BCM4345/6
> > [    3.660643] usbcore: registered new interface driver brcmfmac
> > [    4.041524] brcmfmac: brcmf_c_process_txcap_blob: no txcap_blob
> > available (err=-2)
> > [    4.042269] brcmfmac: brcmf_c_preinit_dcmds: Firmware: BCM4345/6
> > wl0: Oct 28 2024 23:27:00 version 7.45.286 (be70ab3 CY) FWID
> > 01-95efe7fa
> >
> > The only annoyance I get is that the log fills up with failed scan messages:
> > May 07 08:43:11 deskrune wpa_supplicant[604]: wlan0: Failed to
> > initiate sched scan
>
> The scheduled scan is basically a scan offload in which user-space tells
> the driver what to look for and how often (hence scheduled). The
> advantage of the scheduled scan is that the host (RPi) goes to sleep
> while the wifi chip is on the lookout for the ssid. No idea why it is
> failing though.
>
> > the Pi still works and is scanning because when a known ssid appears,
> > it immediately connects, so it is scanning, I just get this message.
>
> What I recall from wpa_supplicant behavior is that it does a regular
> scan for a configured ssid and after a number of attempts it does try to
> setup a scheduled scan if the driver supports it. When it fails it
> simply continues with the regular scans. The brcmfmac driver supports
> scheduled scan so it seems like regression although apart from the log
> message the end-user is not really affected. I expect it will not make
> much noticable difference on the energy bill. ;-)
>
> > Now that I have this working well with wpa_supplicant and know how to
> > get it all 'up' and stable, I will start investigating what
> > differences there are with iwd and why it is flaky. Please guide me as
> > to the best way to do this.
>
> Were you successful using nlmon. I suspect differences should show up
> between wpa_supplicant and iwd.
>
> Regards,
> Arend

I will use nlmon and see what the difference is. Will post them when I get them.

Keith