Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753572AbaA1G1B (ORCPT ); Tue, 28 Jan 2014 01:27:01 -0500 Received: from multi.imgtec.com ([194.200.65.239]:57901 "EHLO multi.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750893AbaA1G07 convert rfc822-to-8bit (ORCPT ); Tue, 28 Jan 2014 01:26:59 -0500 From: Raghu Gandham To: Aaro Koskinen , Dmitry Torokhov CC: "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. Thread-Topic: [PATCH] Input: i8042-io - Exclude mips platforms when allocating/deallocating IO regions. Thread-Index: AQHPGgBYG66oCx9jPE6mIF95ddBIvJqYEzKA//+fccCAAPlRAIAA4b2AgAAbOiA= Date: Tue, 28 Jan 2014 06:25:39 +0000 Message-ID: References: <1390676514-30880-1-git-send-email-raghu.gandham@imgtec.com> <20140126214952.GD18840@core.coreip.homeip.net> <20140127065638.GB11945@core.coreip.homeip.net> <20140127202435.GA589@drone.musicnaut.iki.fi> In-Reply-To: <20140127202435.GA589@drone.musicnaut.iki.fi> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [192.168.150.93] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-SEF-Processed: 7_3_0_01192__2014_01_28_06_26_58 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Aaro, > > 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. This would mean that before your patch in oct of 2012, Loongson and Octeon were not reserving the IO space for i8042. > > 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? The only information I have is the comment before request_region in i8042-io.h that touching data register on some platforms is flaky. If your patch was primarily aimed at addressing the error message from release_region, the current patch I uploaded should also take care of it too. Thanks, Raghu -- 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/