Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263326AbVCEFuC (ORCPT ); Sat, 5 Mar 2005 00:50:02 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263284AbVCEFra (ORCPT ); Sat, 5 Mar 2005 00:47:30 -0500 Received: from gate.crashing.org ([63.228.1.57]:50925 "EHLO gate.crashing.org") by vger.kernel.org with ESMTP id S263407AbVCDXHM (ORCPT ); Fri, 4 Mar 2005 18:07:12 -0500 Subject: Re: [PATCH/RFC] I/O-check interface for driver's error handling From: Benjamin Herrenschmidt To: Pavel Machek Cc: Jesse Barnes , linux-pci@atrey.karlin.mff.cuni.cz, Matthew Wilcox , Linus Torvalds , Jeff Garzik , Hidetoshi Seto , Linux Kernel list , linux-ia64@vger.kernel.org, Linas Vepstas , "Luck, Tony" In-Reply-To: <20050304225710.GB2647@elf.ucw.cz> References: <422428EC.3090905@jp.fujitsu.com> <20050301165904.GN28741@parcelfarce.linux.theplanet.co.uk> <200503010910.29460.jbarnes@engr.sgi.com> <20050304135429.GC3485@openzaurus.ucw.cz> <1109975846.5680.305.camel@gaston> <20050304225710.GB2647@elf.ucw.cz> Content-Type: text/plain Date: Sat, 05 Mar 2005 10:03:37 +1100 Message-Id: <1109977417.5611.318.camel@gaston> Mime-Version: 1.0 X-Mailer: Evolution 2.0.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1052 Lines: 27 On Fri, 2005-03-04 at 23:57 +0100, Pavel Machek wrote: > What prevents driver from being run on another CPU, maybe just doing > mdelay() between hardware accesses? Almost all drivers that I know have some sort of locking. Nothing nasty about it. Besides, you can't expect everything to be as simple as putting two bit of lego together, the problem isn't simple. If an IOs gets there out of sync, it's a non-issue, it will most probably just return all 1's, and if using Seto proposed functions, the bit of code doing it will "know" there was an error and will stop. But a driver notified of errors that, typically, triggered a slot isolation like on pSeries, will have to wait for all IOs to complete anyway, stop everything, so that the slot can be reset. I think you are raising a non-issue. Ben. - 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/