On Tuesday, February 28, 2012, Rajashekhara, Sudhakar <sudhakar.raj-l0cyMroinI0@public.gmane.org> wrote:
> Hi Christian,
>
> On Mon, Feb 27, 2012 at 15:44:54, Rajashekhara, Sudhakar wrote:
>> Hi Christian,
>>
>> On Fri, Feb 24, 2012 at 19:45:23, Christian Riesch wrote:
>> > Hello Sudhakar,
>> >
>> > On Fri, Feb 24, 2012 at 2:02 PM, Rajashekhara, Sudhakar <sudhakar.raj-l0cyMroinI0@public.gmane.org> wrote:
>> > > On Thu, Feb 23, 2012 at 14:39:49, Christian Riesch wrote:
>> > >> Hi,
>> > >> I observed this behavior on a Texas Instruments AM1808 SoC (AM1808
>> > >> experimenter's kit) running the current mainline kernel:
>> > >>
>>
>> [snip]
>>
>> > >>
>> > >> According to the AM1808 Technical Reference Manual (sections 18.2.14.1
>> > >> and 18.3.3.34 in [1]), writing a 1 to the EMAC_SOFTRESET register
>> > >> resets the EMAC module, but not the MDIO module. However, when I
>> > >> comment out the code above, the MDIO control register is not affected
>> > >> and the warning 'resetting idled controller' disappears.
>> > >>
>> > >
>> > > But this was not the case for me. Even after commenting out the above lines,
>> > > I could still see that MDIO was getting reset.
>> >
>> > Uh, I am sorry. I forgot to mention that there is a second
>> > emac_write(EMAC_SOFTRESET,1); in emac_dev_stop() in davinci_emac.c.
>> > This one must also be commented out to make the resetting idled controller
>> > message go away.
>> >
>> > The patch below shows that changes that I did. May I please ask you to try
>> > again with these changes?
>> >
>>
>> I was able to reproduce the issue. I'll debug this further and get back to you.
>>
>
> I was going through the mailing list discussions where a work around for emac
> soft-reset tie-up to mdio controller has been proposed. I think this was a known
> issue on TI's da8xx family of devices. Please refer to the thread at
> http://www.spinics.net/lists/netdev/msg140465.html.
>
> Cyril,
> As you have mentioned in your patch, did you get any confirmation from TI designer
> regarding emac soft reset behavior? I see that nothing has been mentioned in the
> EMAC user guide.

Ping?

Thanks, Christian