From mboxrd@z Thu Jan 1 00:00:00 1970 From: Armin Steinhoff Subject: Re: Converting a device driver for real time kernel - OT Date: Wed, 10 Feb 2010 13:53:33 +0100 Message-ID: <4B72AC4D.2060900@steinhoff-automation.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit To: linux-rt-users@vger.kernel.org Return-path: Received: from moutng.kundenserver.de ([212.227.17.8]:61703 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750933Ab0BJMwW (ORCPT ); Wed, 10 Feb 2010 07:52:22 -0500 In-Reply-To: Sender: linux-rt-users-owner@vger.kernel.org List-ID: Hi all, I know it's OT ... but what is the real name of - "real time kernel (2.6.22.19-0.14-rt)" - "!RT kernel" - "-rt kernel" Any ideas ? Is it the RTP kernel --- P stands for pre-emption ? --Armin Thomas Gleixner wrote: > On Tue, 9 Feb 2010, Leggo, Adam (UK) wrote: > > >> Hello, >> >> What is the best way of converting an existing device driver to work >> under a real-time kernel? >> >> A device driver provided for a special serial card (Curtiss Wright SL240 >> sFDFP card http://www.cwcembedded.com/products/0/1/461.html) works under >> vanilla Linux (SLES SP10 SP2 kernel 2.6.16.60-0.21-smp), but compiling >> the driver under the real time kernel (2.6.22.19-0.14-rt) the system >> locks up and crashes. The rt kernel is being used to write large amounts >> of data from the serial card to disk and testing has found the rt kernel >> has the best consistent write performance. >> >> I have gone back to the supplier and they are not interested in >> developing a real time version of the driver. So I am trying to modify >> the driver myself. The driver code can be provided if anyone wants a >> look (released under GPLv2). >> >> Any assistance would be useful. >> > > The problem of the driver is probably broken locking, which needs to > be fixed for !RT as well. > > But if you want to fix it your self and need some assistance it would > be helpful if you could: > > 1) Run against a recent -rt kernel > > 2) provide a serial console log of the kernel crash > > 3) run the kernel with CONFIG_PROVE_LOCKING=y and provide the output > > 4) upload the source to some place so we can at least have a look at > the code to give you hints. > > Thanks, > > tglx > > -- > To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > >