From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gregkh@linuxfoundation.org>
Date: Thu, 4 Jul 2013 09:19:11 -0700
From: Greg KH <gregkh@linuxfoundation.org>
To: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
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: <CAGH3droX_J9JJ60EP6d62Sh6MK6T5WvYTq+uwcmJkwb0c1Yurg@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
In-Reply-To: <CAGH3droX_J9JJ60EP6d62Sh6MK6T5WvYTq+uwcmJkwb0c1Yurg@mail.gmail.com>
List-ID: <linux-iio@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