From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: What's in libata-dev.git Date: Mon, 11 Sep 2006 16:14:55 -0400 Message-ID: <4505C3BF.8070601@garzik.org> References: <20060911132250.GA5178@havoc.gtf.org> <45056627.7030202@ru.mvista.com> <450566A2.1090009@garzik.org> <450568F3.3020005@ru.mvista.com> <1157986974.23085.147.camel@localhost.localdomain> <45057651.8000404@garzik.org> <1157988513.23085.159.camel@localhost.localdomain> <20060911153706.GE4955@suse.de> <450585DF.1080500@garzik.org> <20060911200112.GA10409@kernel.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:40382 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S965008AbWIKUPD (ORCPT ); Mon, 11 Sep 2006 16:15:03 -0400 In-Reply-To: <20060911200112.GA10409@kernel.dk> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jens Axboe Cc: Alan Cox , Sergei Shtylyov , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, Andrew Morton , Linus Torvalds Jens Axboe wrote: > On Mon, Sep 11 2006, Jeff Garzik wrote: >> Jens Axboe wrote: >>> On Mon, Sep 11 2006, Alan Cox wrote: >>>> We could perhaps do it by ATA version - 255 for ATA < 3 256 for ATA 3+, >>> Might be sane, yep. >> >> Since we're doing this just for paranoia, and nobody can actually >> produce a problem case, it's safer just to hardcode 255 for all cases, >> than try to come up with a hueristic that won't be exercised for another >> decade... > > If it's a real problem, yes I agree. If it's just hand waving, then no. > The fact that 2.4 and 2.6 has been using 256 for ages really tells me > that no one has been affected by this. The SUSE bugzilla certainly > hasn't seen any entries on it either. > >> Most new disks are lba48 anyway. (should we use 65535 there too???) > > Heh, good question. Given that the limit is so high, we might as well > just use 65535. It's not nearly as sensitive as the lba28 case. Well, I _do_ think it's just hand waving, but OTOH I don't see much harm in using 255. Contiguous 256-sector reads and writes have gotta be pretty rare. But that's just a hand-waving guess too ;-) Jeff