Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754306AbaA0UZV (ORCPT ); Mon, 27 Jan 2014 15:25:21 -0500 Received: from filtteri1.pp.htv.fi ([213.243.153.184]:37651 "EHLO filtteri1.pp.htv.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753763AbaA0UZT (ORCPT ); Mon, 27 Jan 2014 15:25:19 -0500 Date: Mon, 27 Jan 2014 22:24:35 +0200 From: Aaro Koskinen To: Dmitry Torokhov Cc: Raghu Gandham , "linux-input@vger.kernel.org" , "linux-mips@linux-mips.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] Input: i8042-io - Exclude mips platforms when allocating/deallocating IO regions. Message-ID: <20140127202435.GA589@drone.musicnaut.iki.fi> References: <1390676514-30880-1-git-send-email-raghu.gandham@imgtec.com> <20140126214952.GD18840@core.coreip.homeip.net> <20140127065638.GB11945@core.coreip.homeip.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140127065638.GB11945@core.coreip.homeip.net> User-Agent: Mutt/1.5.22 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Sun, Jan 26, 2014 at 10:56:38PM -0800, Dmitry Torokhov wrote: > On Mon, Jan 27, 2014 at 12:32:36AM +0000, Raghu Gandham wrote: > > > On Sat, Jan 25, 2014 at 11:01:54AM -0800, Raghu Gandham wrote: > > > > The standard IO regions are already reserved by the platform code on > > > > most MIPS devices(malta, cobalt, sni). The Commit > > > > 197a1e96c8be5b6005145af3a4c0e45e2d651444 > > > > ("Input: i8042-io - fix up region handling on MIPS") introduced a bug > > > > on these MIPS platforms causing i8042 driver to fail when trying to > > > > reserve IO ports. > > > > Prior to the above mentioned commit request_region is skipped on MIPS > > > > but release_region is called. > > > > > > > > This patch reverts commit 197a1e96c8be5b6005145af3a4c0e45e2d651444 > > > > and also avoids calling release_region for MIPS. > > > > > > The problem is that IO regions are reserved on _most_, but not _all_ > > > devices. > > > MIPS should figure out what they want to do with i8042 registers and be > > > consistent on all devices. > > > > Please examine the attached patch which went upstream in April of 2004. > > Since then it had been a convention not to call request_region routine in > > i8042 for MIPS. The attached patch had a glitch that it guarded > > request_region in i8042-io.h but skipped guarding release_region in > > i8042-io.h. I believe that the issue Aaro saw was due to this > > glitch. Below is the error quoted in Aaro's commit message. > > > > [ 2.112000] Trying to free nonexistent resource <0000000000000060-000000000000006f> > > > > My patch reinstates the convention followed on MIPS devices along with > > fixing Aaro's issue. > > I assume that Aaro did test his patch and on his box request_region() > succeeds. That would indicate that various MIPS sub-arches still not > settled on the topic. request_region() succeeds on Loongson and OCTEON. On OCTEONs without PCI, request_region() will fail which is correct as there is no I/O space. I wasn't aware of that 2004 patch (it pre-dates GIT history of mainline Linux). Why the regions are already reserved by the platform code? A. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/