Bug #727

brcmfmac having problems in AP + station mode

Added by Hammel 12 months ago. Updated 12 months ago.

Status:ClosedStart date:27 Oct 2019
Priority:ImmediateDue date:
Assignee:Hammel% Done:


Category:04 - Root File System
Target version:2.0 - Harkonnen
Severity:01 - Critical


In Ironman the brcmfmac wifi is being used in both AP and station mode at the same time. "iw list" shows this configuration is supported. However, if you bring up wlan0 and uap0 as has been done with other wifi dongles the brcmfmac will disconnect the station (wifi client) when it brings up the AP. This seems to be the same as other dongles and the solution was

  1. bring up wlan0
  2. bring up uap0
  3. bring up wlan0 again

But the last step doesn't work with brcmfmac. There is a possible solution here but I've not tried it yet. Some googling shows this driver disables the the station when ap is started and doesn't allow it to come back up. A fix was posted in 2018 but that doesn't appear to be in either RPi Linux 4.19.y or next branch. Not sure if there is a driver fix anywhere else.

Barring a driver fix and the potential workaround fixing this I'll have to disable brcmfmac in Ironman and use a dongle. Disabling will have to include removing or renaming the driver because S10mdev will load the driver automatically if it's there and simply rmmod'ing the driver later will cause the dongle to come up as wlan1, which we don't want.


#1 Updated by Hammel 12 months ago

Also see if the firmware is up to date.
Latest firmware is from 05/2019.
RPi-Distro latest firmware is the same (plux txt file).

#2 Updated by Hammel 12 months ago

  • % Done changed from 0 to 20

New firmware does not fix the problem. The possible workaround doesn't really do anything I'm not already doing. I'm going to try one other thing: bring up wlan0 without wpa_supplicant, bring up uap0 then bring up wpa_supplicant on wlan0.

#3 Updated by Hammel 12 months ago

  • % Done changed from 20 to 50

No, it doesn't work. It's the driver (and/or firmware). I simply can't use it with Ironman.

Falling back to a wifi dongle as we used previously. I'll disable the brcmfmac driver in the build via a config app, like I do with Xeon.

#4 Updated by Hammel 12 months ago

  • Status changed from In Progress to Closed
  • % Done changed from 50 to 100

Completed. I've added the package (ironmancfg) to GitLab and integrated it with Ironman's meta build.

Tested, committed and pused (both the new package and meta).

Closing issue.

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