From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756661Ab1CGWMW (ORCPT ); Mon, 7 Mar 2011 17:12:22 -0500 Received: from imr3.ericy.com ([198.24.6.13]:49561 "EHLO imr3.ericy.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756615Ab1CGWMT (ORCPT ); Mon, 7 Mar 2011 17:12:19 -0500 Date: Mon, 7 Mar 2011 14:11:29 -0800 From: Guenter Roeck To: Greg Schnorr CC: Jean Delvare , Jonathan Cameron , Randy Dunlap , "lm-sensors@lm-sensors.org" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] hwmon: (pmbus) More stringent checking of VOUT_MODE register Message-ID: <20110307221129.GC14789@ericsson.com> References: <1299043940-22798-1-git-send-email-guenter.roeck@ericsson.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 07, 2011 at 04:44:43PM -0500, Greg Schnorr wrote: > Looks good, tested and works on one such VOUT_MODE poor design... > > On 3/1/11 9:32 PM, "Guenter Roeck" wrote: > > > Some PMBus chips do not support the VOUT_MODE register. To make matters worse, > > such chips may not return an error when reading the register either, but > > instead > > return 0xff. > > > > Check if the register exists using pmbus_check_byte_register() before reading > > its value. In addition, validate the returned value and ignore it if it is > > 0xff > > (which is invalid). > > > > Reported-by: Greg Schnorr > > Signed-off-by: Guenter Roeck > Acked-by: Greg Schnorr > Thanks! Guenter