[LEDE-DEV] Concerning the switch to dwc2 on Danube

[Ben Mulvihill]

On Wed, 2016-12-28 at 19:26 +0000, Mohammed Berdai wrote:
> Hi,
> 
> I managed to test the latest LEDE commits after missing daily tests for a few weeks due to a busy schedule.
> 
> The switch to dwc2 module caused kernel panics on ARV4518pw, ARV7518pw and ARV7510pw22.
> 
> I tracked LEDE git repo till I reached these:
> 
> lantiq: use dwc2 by default on danube
> ffd7c155008bff4b08197dfd710d7a1386313f98
> 
> lantiq: dwc2 parameters for danube
> 6f60926babe50cd1aa24fb849577fff9fe7f46b4
> 
> lantiq: device tree bindings for dwc2 on danube
> 5c06a31e23b9cc1b8c8a1a8e0ab58353fc925865
> 
> lantiq: initialise dwc2 on danube
> c82d5b30e10e6987bb73119c2c08ec9ff4a504dd 
> 
> When I reverted them all three routers went back to normal.
> 
> I reported this issue with bootlogs here:
> 
> https://bugs.lede-project.org/index.php?do=details&task_id=350
> 
> https://bugs.lede-project.org/index.php?do=details&task_id=351
> 
> It would be great if we can resolve this issue before LEDE first stable release.
> 
> I can help you doing tests and report back to you.
> 
> Regards,
> 
> Mohammed

Oh dear! Sorry about that.

I've put the Lede mailing list on copy.

It looks from the boot logs as though the dwc2 driver does
not handle the gpio request correctly. I tested my changes
on a BTHOMEHUBV2B which does not request a specific gpio.
Your Arcadian boards do.

As a quick fix it should be enough to revert commit 
ffd7c155008bff4b08197dfd710d7a1386313f98
(lantiq: use dwc2 by default on danube)
without reverting the other two. That way the old driver is
used by default but dwc2 is still available for those boards
where it does work.

If time is too short to sort out the gpio problem before the
freeze for the first stable release I could do a patch to
make dwc2 the default on the BTHOMEHUBV2B only, leaving the
old driver as the default on the other danube boards.
 
Regards,

Ben