From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.gmx.net (mail.gmx.net [213.165.64.20]) by ozlabs.org (Postfix) with SMTP id F1A21B7BBA for ; Fri, 4 Dec 2009 02:10:03 +1100 (EST) Message-ID: <4B17D4C5.3070100@gmx.de> Date: Thu, 03 Dec 2009 16:09:57 +0100 From: Michael Lawnick MIME-Version: 1.0 To: Ben Dooks Subject: Re: [PATCH v2] i2c-mpc: generate START condition after STOP caused by read i2c_msg References: <4A124202.4010201@doredevelopment.dk> <20090526213351.GG23114@fluff.org.uk> In-Reply-To: <20090526213351.GG23114@fluff.org.uk> Content-Type: text/plain; charset=ISO-8859-1 Cc: linuxppc-dev@ozlabs.org, Esben Haabendal , Esben Haabendal , linux-i2c@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Ben Dooks said the following: > On Tue, May 26, 2009 at 01:30:21PM +0200, Esben Haabendal wrote: >> On Tue, May 19, 2009 at 7:22 AM, Esben Haabendal wrote: >> > This fixes MAL (arbitration lost) bug caused by illegal use of >> > RSTA (repeated START) after STOP condition generated after last byte >> > of reads. With this patch, it is possible to do an i2c_transfer() with >> > additional i2c_msg's following the I2C_M_RD messages. >> > >> > It still needs to be resolved if it is possible to fix this issue >> > by removing the STOP condition after reads in a robust way. >> > >> > Signed-off-by: Esben Haabendal >> > --- >> > ?drivers/i2c/busses/i2c-mpc.c | ? ?9 +++++++-- >> > ?1 files changed, 7 insertions(+), 2 deletions(-) >> >> Any blockers to get this accepted? > > It would be nice to get an ack from someone who can actually test > the driver before getting this merged. > What is the state of this patch? Shouldn't we attack the problem on a more general way by inventing a Flag I2C_M_RESTART (or better I2C_M_NO_RESTART for backward compatibility)? This way the client driver is able to decide what it needs. If we do the choice within adapter, chance is about 50% to be wrong. Just my 2 Cents. -- Michael