From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stanislaw Gruszka Subject: Re: [RFC][PATCH] at91_ide driver Date: Thu, 22 Jan 2009 12:19:19 +0100 Message-ID: <200901221219.19504.stf_xl@wp.pl> References: <200901141345.42583.stf_xl@wp.pl> <20090114135832.7718055f@hskinnemoen-d830> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mx1.wp.pl ([212.77.101.5]:16823 "EHLO mx1.wp.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753863AbZAVLT2 convert rfc822-to-8bit (ORCPT ); Thu, 22 Jan 2009 06:19:28 -0500 In-Reply-To: <20090114135832.7718055f@hskinnemoen-d830> Content-Disposition: inline Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Haavard Skinnemoen Cc: Andrew Victor , Nicolas Ferre , linux-ide@vger.kernel.org Wednesday 14 January 2009 13:58:32 Haavard Skinnemoen napisa=C5=82(a): > Stanislaw Gruszka wrote: > > Some issues with driver: > >=20 > > * Why not platform driver > > Generic pata/ide_platform driver will not work with AT91 as we need= to=20 > > do special things before access Task File and Data Register (functi= ons=20 > > set_8bit_mode() and set_16bit_mode()). Also extra things needs to b= e > > done when changing PIO mode. >=20 > Why not use libata? There's already a pata_at32 driver there which > should be usable on at91 with perhaps a few minor changes. I will submit at91_ide for the mainline and not touch pata_at32 for re= ason listed below (some of them was already mentioned in this thread): * there are difference in h/w attend=20 - AT91 and AT32 static memory controller h/w is the same, but linux s= oftware=20 interface to programing SMC is diffrent (in this driver we need to = program SMC) - AT91 have to switch between 8/16 bit data bus width, AT32 not - AT32 not need to have GPIO IRQ quirk * libata have more overhead due to SCSI emulation * ide maintainer is likely to accept at91_ide * my company want to use it in production with older kernel Cheers Stanislaw Gruszka