From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Date: Tue, 01 Mar 2005 14:42:11 +0000 Subject: Re: [PATCH/RFC] I/O-check interface for driver's error handling Message-Id: <20050301144211.GI28741@parcelfarce.linux.theplanet.co.uk> List-Id: References: <422428EC.3090905@jp.fujitsu.com> In-Reply-To: <422428EC.3090905@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Hidetoshi Seto Cc: Linux Kernel list , linux-pci@atrey.karlin.mff.cuni.cz, linux-ia64@vger.kernel.org, Linus Torvalds , Benjamin Herrenschmidt , Linas Vepstas , "Luck, Tony" On Tue, Mar 01, 2005 at 05:33:48PM +0900, Hidetoshi Seto wrote: > Today's patch is 3rd one - iochk_clear/read() interface. > - This also adds pair-interface, but not to sandwich only readX(). > Depends on platform, starting with ioreadX(), inX(), writeX() > if possible... and so on could be target of error checking. I'd prefer to see it as ioerr_clear(), ioerr_read() ... > - Additionally adds special token - abstract "iocookie" structure > to control/identifies/manage I/Os, by passing it to OS. > Actual type of "iocookie" could be arch-specific. Device drivers > could use the iocookie structure without knowing its detail. Fine. > If arch doesn't(or cannot) have its io-checking strategy, these > interfaces could be used as a replacement of local_irq_save/restore > pair. Therefore, driver maintainer can write their driver code with > these interfaces for all arch, even where checking is not implemented. But many drivers don't need to save/restore interrupts around IO accesses. I think defaulting these to disable and restore interrupts is a very bad idea. They should probably be no-ops in the generic case. -- "Next the statesmen will invent cheap lies, putting the blame upon the nation that is attacked, and every man will be glad of those conscience-soothing falsities, and will diligently study them, and refuse to examine any refutations of them; and thus he will by and by convince himself that the war is just, and will thank God for the better sleep he enjoys after this process of grotesque self-deception." -- Mark Twain