Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753629AbbFXOE7 (ORCPT ); Wed, 24 Jun 2015 10:04:59 -0400 Received: from nopam.alitech.com ([202.3.176.31]:57047 "EHLO nopam.alitech.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753257AbbFXOEu (ORCPT ); Wed, 24 Jun 2015 10:04:50 -0400 split_mail: 1 In-Reply-To: <1435150578.1075.5.camel@intel.com> References: <1433785828-4100-1-git-send-email-lucas.de.marchi@gmail.com> <20150609085146.GD1478@lahna.fi.intel.com> <20150610070722.GM1478@lahna.fi.intel.com> <20150624112723.GE827@lahna.fi.intel.com> <1435150578.1075.5.camel@intel.com> To: "De Marchi, Lucas" Cc: "christian.ruppert@abilis.com" , "Mello, Fabio" , "jarkko.nikula@linux.intel.com" , "linux-i2c@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "lucas.de.marchi@gmail.com" , "mika.westerberg@linux.intel.com" , "wsa@the-dreams.de" Subject: Re: [PATCH] i2c: designware: use enable on resume instead initialization MIME-Version: 1.0 X-KeepSent: F6E472DA:067DC73F-C1257E6E:004C4637; type=4; name=$KeepSent X-Mailer: Lotus Notes Release 8.5.3 September 15, 2011 Message-ID: From: christian.ruppert@alitech.com Date: Wed, 24 Jun 2015 16:06:45 +0200 X-MailConfidential: Public X-MIMETrack: Serialize by Router on TWALINS2/ALI_TPE/ALi(Release 8.0.2FP6|July 15, 2010) at 2015/06/24 ?? 10:06:50, Serialize complete at 2015/06/24 ?? 10:06:50 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2316 Lines: 71 Dear Lucas, "De Marchi, Lucas" wrote on 24.06.2015 14:56:19: > On Wed, 2015-06-24 at 14:27 +0300, Mika Westerberg wrote: > > On Wed, Jun 24, 2015 at 09:36:43AM +0200, christian.ruppert@alitech.com wrot > > e: > > > Dear Lucas, > > > > > > Lucas De Marchi wrote on 23.06.2015 19:02:03: > > > > On Tue, Jun 23, 2015 at 1:45 PM, wrote: > > > > > Hello, > > > > > > > > > > Christian Ruppert/ALi_GVA/ALi wrote on 10.06.2015 17:05:16: > > > > [...] > > > > > The result is not very encouraging: Out of five (identical) > designware > > > > > > > > i2c > > > > > controllers we have on my test SOC, the first one > initialises properly > > > > > > > > but > > > > > the second one gets stuck in the famous irq loop right away when the > > > > > module is enabled in i2c_dw_init. The system never gets around to try > > > > > > > > Are you using the pci or platform driver? I noticed yesterday the pci > > > > version is failing here with a NULL pointer dereference. > > > > > > The test was performed with the platform driver (instantiated through > > > device tree). > > > I just re-checked and the ultimate problem which hangs/kills thesystem in > > > > > > my case is the IRQ loop. > > > I haven't observed any NULL pointer dereferences on the road. > > > > Thanks Christian for testing. > > > > Since the patch causes problems on your hardware, I don't think it is > > good idea to merge it. > > > Yeah, but it would be bad to ignore the problem as well. The way it is now > kills any possibility of using DW controller for reading sensors like > gyroscope, accelerometer, barometer that have higher sampling rate etc. I'll > try to come up with a new patch but since I can't reproduce the problem here > it'd be good to know if there's any means for me to test. I'll analyse the problem a bit further and send you a description (sda and scl state at enable time) as soon as I can put my hands on an oscilloscope one evening. Greetings, Christian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/