Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756464AbcK2JE7 (ORCPT ); Tue, 29 Nov 2016 04:04:59 -0500 Received: from mga14.intel.com ([192.55.52.115]:15022 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756363AbcK2JEh (ORCPT ); Tue, 29 Nov 2016 04:04:37 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,715,1473145200"; d="scan'208";a="1091940978" Date: Tue, 29 Nov 2016 11:04:31 +0200 From: Mika Westerberg To: Tin Huynh Cc: Jarkko Nikula , Andy Shevchenko , Wolfram Sang , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, Loc Ho , Thang Nguyen , Phong Vo , patches@apm.com Subject: Re: [PATCH V1] i2c: designware: fix wrong tx/rx fifo for ACPI Message-ID: <20161129090431.GM1459@lahna.fi.intel.com> References: <1480390327-24562-1-git-send-email-tnhuynh@apm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1480390327-24562-1-git-send-email-tnhuynh@apm.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.7.1 (2016-10-04) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 485 Lines: 11 On Tue, Nov 29, 2016 at 10:32:07AM +0700, Tin Huynh wrote: > ACPI always sets txfifo and rxfifo to 32. This configuration will > cause problem if the IP core supports a fifo size of 16 bytes only. > Set the default value to 0 so the driver will get these parameters > from IP core. Except when those values are not available which is the reason why we have the default 32 for ACPI systems. Are you saying you have DW I2C controller on ACPI system where the FIFO is smaller than 32?