From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rajashekhara, Sudhakar" Subject: RE: davinci_emac/mdio: SOFT_RESET of EMAC module resets MDIO on AM1808 Date: Mon, 27 Feb 2012 10:15:03 +0000 Message-ID: References: <1330092923-10899-1-git-send-email-christian.riesch@omicron.at> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Cc: "netdev@vger.kernel.org" , "davinci-linux-open-source@linux.davincidsp.com" , "Chemparathy, Cyril" , "Gole, Anant" To: Christian Riesch Return-path: Received: from arroyo.ext.ti.com ([192.94.94.40]:33791 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753534Ab2B0KPW convert rfc822-to-8bit (ORCPT ); Mon, 27 Feb 2012 05:15:22 -0500 In-Reply-To: <1330092923-10899-1-git-send-email-christian.riesch@omicron.at> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: 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 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. Regards, Sudhakar