From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264098AbUE1Waa (ORCPT ); Fri, 28 May 2004 18:30:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264117AbUE1WHc (ORCPT ); Fri, 28 May 2004 18:07:32 -0400 Received: from mail.kroah.org ([65.200.24.183]:37310 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S264119AbUE1WBb convert rfc822-to-8bit (ORCPT ); Fri, 28 May 2004 18:01:31 -0400 Subject: Re: [PATCH] I2C update for 2.6.7-rc1 In-Reply-To: <10857816431154@kroah.com> X-Mailer: gregkh_patchbomb Date: Fri, 28 May 2004 15:00:43 -0700 Message-Id: <10857816431296@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII To: linux-kernel@vger.kernel.org, sensors@stimpy.netroedge.com Content-Transfer-Encoding: 7BIT From: Greg KH Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org ChangeSet 1.1717.6.28, 2004/05/19 00:26:34-07:00, ebs@ebshome.net [PATCH] I2C PPC4xx IIC driver: 0-length transaction temporary fix this patch adds temporary fix for 0-length requests (e.g. SMBUS_QUICK) to PPC4xx IIC driver. This i2c controller doesn't support such transactions and this patch just restores previous driver version behavior making SMBUS_QUICK-based bus scan at least partially usable. This is temporary kludge until correct bit-banging emulation is implemented. drivers/i2c/busses/i2c-ibm_iic.c | 10 ++++++++++ 1 files changed, 10 insertions(+) diff -Nru a/drivers/i2c/busses/i2c-ibm_iic.c b/drivers/i2c/busses/i2c-ibm_iic.c --- a/drivers/i2c/busses/i2c-ibm_iic.c Fri May 28 14:52:12 2004 +++ b/drivers/i2c/busses/i2c-ibm_iic.c Fri May 28 14:52:12 2004 @@ -455,6 +455,16 @@ } for (i = 0; i < num; ++i){ if (unlikely(msgs[i].len <= 0)){ + if (num == 1 && !msgs[0].len){ + /* Special case for I2C_SMBUS_QUICK emulation. + * Although this logic is FAR FROM PERFECT, this + * is what previous driver version did. + * IBM IIC doesn't support 0-length transactions + * (except bit-banging through IICx_DIRECTCNTL). + */ + DBG("%d: zero-length msg kludge\n", dev->idx); + return 0; + } DBG("%d: invalid len %d in msg[%d]\n", dev->idx, msgs[i].len, i); return -EINVAL;