From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Glauber Subject: Re: [PATCH v6 07/19] i2c: octeon: Use i2c recovery framework Date: Thu, 21 Apr 2016 19:51:10 +0200 Message-ID: <20160421175110.GA2710@hardcore> References: <20160420213121.GC1546@katana> <20160421130835.GA2623@hardcore> <20160421135450.GA5566@katana> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Received: from mail-bn1on0096.outbound.protection.outlook.com ([157.56.110.96]:2149 "EHLO na01-bn1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751611AbcDURv2 (ORCPT ); Thu, 21 Apr 2016 13:51:28 -0400 Content-Disposition: inline In-Reply-To: <20160421135450.GA5566@katana> Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: Wolfram Sang Cc: linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, David Daney On Thu, Apr 21, 2016 at 03:54:50PM +0200, Wolfram Sang wrote: > > > I assumed this check was bogus and there are no valid 0-length > > messages... > > They are valid (check SMBUS_QUICK), but not every controller can handle > them correctly. Your driver has SMBUS_QUICK enabled, so this is a > contradiction to the check above where it rejects it. Oops, this mismatch dates back to the inital driver code. From the documentation I would say SMBUS_QUICK is not supported, although nothing terrible happens in the write case. > So, it looks like it needs to be tested again (and documented this > time). If the HW can't do it, the FUNC bit for QUICK needs to be masked > out. If it can do SMBUS_QUICK, the check can probably go away. > I would like to disable SMBUS_QUICK. It never worked for the read case. Could we break something by disabling the quick-write case or is the quick-write emulated by a larger write if the feature bit is not set?