From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756812Ab3GDQSV (ORCPT ); Thu, 4 Jul 2013 12:18:21 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:47907 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756525Ab3GDQSU (ORCPT ); Thu, 4 Jul 2013 12:18:20 -0400 Date: Thu, 4 Jul 2013 09:19:11 -0700 From: Greg KH To: Oleksandr Kravchenko Cc: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, arnd@arndb.de, jic23@cam.ac.uk Subject: Re: Issue with porting i2c driver to k3.10 (iio) Message-ID: <20130704161911.GC20907@kroah.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 04, 2013 at 04:16:43PM +0300, Oleksandr Kravchenko wrote: > Hi All, > > I wrote i2c driver for APDS-9300 light sensor in drivers/misc, but I have some > questions regarding upstreaming of it. > 1. It works properly in kernel-3.4, but it works very slow in kernel-3.10 (on > mutex and i2c operations, particulary on mutex_lock() and i2c_smbus_read_data > ()). Does anyone know why this issue may be occurred? What is "slow"? Have you run 'perf' on the driver to see where it is spending time? > 2. Can I send this driver without using Industrial I/O framework? No, why would you even want to? greg k-h