[FS#427] Switch broken with WRT3200ACM (removes wifi adapters and break vlan bridges)

[LEDE Bugs]

A new Flyspray task has been opened.  Details are below. 

User who did this - bentiss (bentiss) 

Attached to Project - LEDE Project
Summary - Switch broken with WRT3200ACM (removes wifi adapters and break vlan bridges)
Task Type - Bug Report
Category - Base system
Status - Unconfirmed
Assigned To - 
Operating System - All
Severity - Medium
Priority - Very Low
Reported Version - Trunk
Due in Version - Undecided
Due Date - Undecided
Details -  - Device problem occurs on:

WRT3200ACM

 - Software versions of LEDE release, packages, etc.:

master tree (and v17.01), bisected to f24ffb901e0408917748773b883841eca52eea05.

 - Steps to reproduce

* Flash a recent LEDE snapshot on the WRT3200ACM (and factory reset),
* enable wifi (2 or 5 Gz) -> Wifi works
* disable wifi -> errors in the dmesg about not being able to set a feature (can't remember the exact error)
* re-enable wifi -> errors in the dmesg saying that the adapter does not exist. This gets shouted in the dmesg every 5 seconds

A reboot doesn't fix the issue. I need to downgrade the firmware prior to f24ffb901e0408917748773b883841eca52eea05 and factory reset to get the wifi adapters back.

For the Vlan bridge, symptoms are easier to detect:
* create a new adapter bridged on eth0.100 eth1.100
* no traffic goes through it. An snapshot before f24ffb901 used to work
(the setup is the Free french provider which has a vlan between the modem and the TV adapter over VLAN 100. So the LEDE box should act like a pass-through here only)

I bisected to the commit mentioned above (which, to me seems suspicious given that the driver is for mvsw61xx and the switch in the WRT3200ACM is MV88E6352, so a different generation). I don't have enough knowledge of the chip to understand why this fails, but I don't feel confident enough to simply send a PR with the revert.

Reverting f24ffb901e on top of master makes the Wifi and VLAN back to normal.

 

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=427