From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752167AbbJEGsb (ORCPT ); Mon, 5 Oct 2015 02:48:31 -0400 Received: from mail-wi0-f193.google.com ([209.85.212.193]:33502 "EHLO mail-wi0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751104AbbJEGsa (ORCPT ); Mon, 5 Oct 2015 02:48:30 -0400 MIME-Version: 1.0 In-Reply-To: <56118304.8020002@lysator.liu.se> References: <560F0DB1.2020101@lysator.liu.se> <56118304.8020002@lysator.liu.se> From: Christian Gmeiner Date: Mon, 5 Oct 2015 08:16:56 +0200 Message-ID: Subject: Re: Regression: at24 eeprom writing To: Peter Rosin Cc: Linux Kernel Mailing List , Wolfram Sang , "linux-arm-kernel@lists.infradead.org" , Ludovic Desroches Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Peter. Sorry for the late answer - I am currently on my way to Dublin. Maybe it helps if you enable I2C_DEBUG_CORE and I2C_DEBUG_BUS. In theory you should see a little bit better what happens on the bus. Greets -- Christian Gmeiner, MSc https://soundcloud.com/christian-gmeiner 2015-10-04 21:50 GMT+02:00 Peter Rosin : > On 2015-10-03 01:05, Peter Rosin wrote: >> I looked around and found that if I revert a839ce663b3183209fdf7b1fc4796bfe2a4679c3 >> "eeprom: at24: extend driver to allow writing via i2c_smbus_write_byte_data" >> eeprom writing starts working again. >> >> AFAICT, the i2c-at91 bus driver makes the eeprom driver use the >> i2c_transfer code path both with that patch and with it reverted, >> so I sadly don't see why the patch makes a difference. > > And now when I retry the same thing, that patch is no longer affecting things. > I must have confused myself over what kernel was actually running. Christian, > please accept my deepest apologies for implicating you in this regression. > > But the regression is still there. In short, linux-3.18-at91 from the > linux4sam tree works, linux-4.1-at91 from the same tree does not, and > vanilla 4.2 also doesn't work. I have a hard time bisecting this thing > though, since the last known good version has a long list of atmel > patches that I refuse to even try to rebase... > > Ideas still welcome of course. > > Cheers, > Peter