From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756637Ab1JYPKJ (ORCPT ); Tue, 25 Oct 2011 11:10:09 -0400 Received: from mail.fuel7.com ([74.222.0.51]:35088 "EHLO mail.fuel7.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751243Ab1JYPKH (ORCPT ); Tue, 25 Oct 2011 11:10:07 -0400 Message-ID: <4EA6D14D.6060800@fuel7.com> Date: Tue, 25 Oct 2011 10:10:05 -0500 From: Kyle Manna User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:7.0.1) Gecko/20110929 Thunderbird/7.0.1 MIME-Version: 1.0 To: Mark Brown CC: linux-kernel@vger.kernel.org, Samuel Ortiz , Jorge Eduardo Candelaria , Liam Girdwood Subject: Re: [PATCH v2 1/6] mfd: TPS65910: Handle non-existent devices References: <1319475964-10841-1-git-send-email-kyle.manna@fuel7.com> <1319475964-10841-2-git-send-email-kyle.manna@fuel7.com> <20111025071417.GE2919@opensource.wolfsonmicro.com> In-Reply-To: <20111025071417.GE2919@opensource.wolfsonmicro.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/25/2011 02:14 AM, Mark Brown wrote: > On Mon, Oct 24, 2011 at 12:05:59PM -0500, Kyle Manna wrote: >> Attempt to read the first register of the device, if there is no >> device return -ENODEV > Can you check for a known value in any of the registers? Unfortunately on this chip there aren't any identification or constant test registers. The only register close is the JTAGVERNUM_REG and that's will change across silicon revisions. - Kyle