From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762003AbbEERaA (ORCPT ); Tue, 5 May 2015 13:30:00 -0400 Received: from smtp-out-181.synserver.de ([212.40.185.181]:1061 "EHLO smtp-out-181.synserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761986AbbEER35 (ORCPT ); Tue, 5 May 2015 13:29:57 -0400 X-SynServer-TrustedSrc: 1 X-SynServer-AuthUser: lars@metafoo.de X-SynServer-PPID: 18336 Message-ID: <5548FE07.7040404@metafoo.de> Date: Tue, 05 May 2015 19:29:43 +0200 From: Lars-Peter Clausen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.6.0 MIME-Version: 1.0 To: Michael Welling , jic23@kernel.org, knaack.h@gmx.de, pmeerw@pmeerw.net, san@rosetechnology.dk, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org Subject: Re: [PATCH] iio: mcp320x: Fix occasional incorrect readings References: <1430843395-19446-1-git-send-email-mwelling@ieee.org> In-Reply-To: <1430843395-19446-1-git-send-email-mwelling@ieee.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/05/2015 06:29 PM, Michael Welling wrote: > Without the cacheline alignment, the readings will occasionally incorrectly > return 0. > > Signed-off-by: Michael Welling > --- > drivers/iio/adc/mcp320x.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/iio/adc/mcp320x.c b/drivers/iio/adc/mcp320x.c > index efbfd12..46b98cf 100644 > --- a/drivers/iio/adc/mcp320x.c > +++ b/drivers/iio/adc/mcp320x.c > @@ -60,7 +60,7 @@ struct mcp320x { > struct spi_message msg; > struct spi_transfer transfer[2]; > > - u8 tx_buf; > + u8 tx_buf ____cacheline_aligned; > u8 rx_buf[2]; The buffers should probably be moved at the end, e.g. reg will still be on the same cacheline. > > struct regulator *reg;