Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754444AbXLNOeH (ORCPT ); Fri, 14 Dec 2007 09:34:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752019AbXLNOd4 (ORCPT ); Fri, 14 Dec 2007 09:33:56 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:55408 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752015AbXLNOdz (ORCPT ); Fri, 14 Dec 2007 09:33:55 -0500 Date: Fri, 14 Dec 2007 15:33:28 +0100 From: Ingo Molnar To: Alan Cox Cc: unlisted-recipients: no@elvis.elte.hu, To-header@elvis.elte.hu, on@elvis.elte.hu, "input <"@elvis.elte.hu, "; Rene Herman" , Paul Rolland , "H. Peter Anvin" , Krzysztof Halasa , Pavel Machek , Andi Kleen , linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar , rol@witbe.net Illegal-Object: Syntax error in Cc: addresses found on vger.kernel.org: Cc: ;Rene Herman ^-extraneous tokens in mailbox, missing end of mailbox Illegal-Object: Syntax error in Cc: addresses found on vger.kernel.org: Cc: ;Rene Herman ^-extraneous tokens in mailbox, missing end of mailbox Subject: Re: RFC: outb 0x80 in inb_p, outb_p harmful on some modern AMD64 with MCP51 laptops Message-ID: <20071214143328.GB10130@elte.hu> References: <475EACB8.7080608@keyaccess.nl> <20071211163706.2dc82275@tux.DEF.witbe.net> <475EB263.2050405@keyaccess.nl> <475EC1C0.2040000@reed.com> <20071211173231.2b87a81f@the-village.bc.nu> <475EE2CA.6020601@reed.com> <475F23BD.3040903@reed.com> <20071212161245.3f388229@the-village.bc.nu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20071212161245.3f388229@the-village.bc.nu> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1549 Lines: 61 * Alan Cox wrote: > There is another reason we can't just do a dumb changeover - two > actually > > #1: Some drivers are using inb_p/outb_p in PCI cases which are going > #to cause PCI posting changes. Most are probably just wrong in the > #first place but they need hand checking hm, any intelligent way to force PCI posting? I guess not. here's a list of candidate drivers (match the out*_p() pattern and do pci) ./char/epca.c ./char/sonypi.c ./scsi/megaraid.c ./ide/pci/serverworks.c ./ide/pci/cmd640.c ./input/mouse/pc110pad.c ./i2c/busses/i2c-amd756.c ./i2c/busses/i2c-ali15x3.c ./i2c/busses/i2c-ali1563.c ./i2c/busses/i2c-ali1535.c ./i2c/busses/i2c-viapro.c ./i2c/busses/i2c-nforce2.c ./i2c/busses/i2c-i801.c ./i2c/busses/i2c-piix4.c ./hwmon/vt8231.c ./hwmon/via686a.c ./hwmon/sis5595.c ./telephony/ixj.c ./net/irda/donauboe.c ./watchdog/pcwd_pci.c ./watchdog/wdt_pci.c > #2: We've got SMP cases that only 'work' because the odds of splitting > the outb and the following port 0x80 cycle, which locks the bus, are tiny. > > That is we've got > > CPU1 CPU2 > main path irq path > outb > outb > > inb 0x80 > inb 0x80 > > races in one or two spots. which seems to suggest we are better off not doing the port 0x80 trick at all. Ingo -- 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/