[U-Boot] [PATCH] net: asix: Fix ASIX 88772B with driver model

[Marcel Ziswiler <marcel.ziswiler@toradex.com>]

On Thu, 2016-08-04 at 11:12 +0200, Marek Vasut wrote:
> On 08/04/2016 11:07 AM, Alban Bedel wrote:
> > 
> > On Wed, 3 Aug 2016 15:23:30 +0000
> > Marcel Ziswiler <marcel.ziswiler@toradex.com> wrote:
> > 
> > > 
> > > On Wed, 2016-08-03 at 15:51 +0200, Marek Vasut wrote:
> > > > 
> > > > On 08/03/2016 11:46 AM, Alban Bedel wrote:
> > > > > 
> > > > > 
> > > > > On Wed, 3 Aug 2016 09:00:42 +0200
> > > > > Marek Vasut <marex@denx.de> wrote:
> > > > > 
> > > > > > 
> > > > > > 
> > > > > > On 08/03/2016 07:32 AM, Alban Bedel wrote:
> > > > > > > 
> > > > > > > 
> > > > > > > Commit 147271209a9d ("net: asix: fix operation without
> > > > > > > eeprom")
> > > > > > > added a special handling for ASIX 88772B that enable
> > > > > > > another
> > > > > > > type of header. This break the driver in DM mode as the
> > > > > > > extra
> > > > > > > handling
> > > > > > > needed in the receive path is missing.
> > > > > > So add the extra handling ?
> > > > > I can do that too, but I though u-boot preferred to avoid
> > > > > useless
> > > > > code.
> > > > Yes, if it is useless.
> > > > 
> > > > > 
> > > > > 
> > > > > > 
> > > > > > 
> > > > > > > 
> > > > > > > 
> > > > > > > However this new header mode is not required and only
> > > > > > > seems to
> > > > > > > increase the code complexity, so this patch revert this
> > > > > > > part of
> > > > > > > commit 147271209a9d.
> > > > > > Why is it not required ?
> > > > > It works fine without, since 2012. In fact this change is not
> > > > > even
> > > > > mentioned in the log of commit 147271209a9d, so I really
> > > > > don't know
> > > > > why
> > > > > it was added in the first place. As can be seen in the revert
> > > > > all
> > > > > it
> > > > > does is adding 2 bytes to the USB packets that are then just
> > > > > skipped.
> > > > > Seems pretty useless to me.
> > > > I would like to get some feedback on this from Marcel, since he
> > > > added
> > > > this stuff.
> > > Yes, sorry. I just came back from vacation and started looking
> > > into it
> > > now. As far as I remember on our hardware without this Ethernet
> > > did not
> > > quite work reliably. This also means that with driver model so
> > > far it
> > > does not work for us which I fed back to Simon once but so far
> > > this has
> > > not been resolved. That fix came from some early U-Boot work done
> > > by
> > > Antmicro way back and I am missing some of the history.
> > Then I'll do a new patch that just fix the driver model receive
> > path.
> Hold on. Marcel, can you maybe test if removing this code has any
> impact
> on the behavior now ?

Sorry for the delay. I tested Alban's patch now both on Toradex Colibri
T20 as well as T30 and its on-module ASIX USB-to-Ethernet chip actually
works perfectly aside from the occasional EHCI timed out on TD -
token=0x88008d80 Rx: failed to receive: -5 message which last I checked
with Simon is still unresolved but was already there long before any of
the driver model work started.

Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Tested-on: Colibri T20/T30 on Colibri Evaluation Board