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....@ti.com> 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. Thanks, Sudhakar _______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
