Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261350AbTEHMIn (ORCPT ); Thu, 8 May 2003 08:08:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261355AbTEHMIn (ORCPT ); Thu, 8 May 2003 08:08:43 -0400 Received: from mion.elka.pw.edu.pl ([194.29.160.35]:9461 "EHLO mion.elka.pw.edu.pl") by vger.kernel.org with ESMTP id S261350AbTEHMId (ORCPT ); Thu, 8 May 2003 08:08:33 -0400 Date: Thu, 8 May 2003 14:20:35 +0200 (MET DST) From: Bartlomiej Zolnierkiewicz To: Jens Axboe cc: Linus Torvalds , Linux Kernel Subject: Re: [PATCH] 2.5 ide 48-bit usage In-Reply-To: <20030508115950.GQ823@suse.de> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3702 Lines: 109 On Thu, 8 May 2003, Jens Axboe wrote: > On Thu, May 08 2003, Bartlomiej Zolnierkiewicz wrote: > > > > On Thu, 8 May 2003, Jens Axboe wrote: > > > On Wed, May 07 2003, Jens Axboe wrote: > > > > > Jens you your patch sets hwif->rqsize to 65535 in setup-pci.c for all > > > > > PCI hwifs which is simply wrong as not all of them supports LBA48. > > > > > You should check for hwif->addressing and if true set rqsize to 65536 > > > > > (not 65535) and not in IDE PCI code but in ide_init_queue() in ide-probe.c. > > > > > > > > Yes you are right, that would be the best way of doing it. As it happens > > > > for that patch, it does not hurt or break anything. But it is certainly > > > > cleaner, I'll fix that up. > > > > > > That part is added, I still kept it at 65535 though akin to how we don't > > > use that last sector in 28-bit commands either. For 48-bit commands this > > > > No, ide_init_queue() sets it to 256, so I want 65536 too. > > Alright, I don't care enough about that 1 sector to argue. > > > Note that it should be done after setting queue max sectors to 256, > > because not only ide-disk depends on this code: > > > > max_sectors = 256; > > > > (...) > > > > /* > > * Added "< max_sectors" check for safety if it will > > * be called again later with rq->size = 65536. > > * I don't believe it ever is. > > */ > > if (hwif->rqsize < max_sectors) > > max_sectors = hwif->rqsize; > > blk_queue_max_sectors(q, max_sectors); > > if (!hwif->rqsize) > > hwif->rqsize = hwif->addressing ? 65536 : 256; > > You have the logic reversed here, the hwif and drive addressing are > reversed. Yeah, it's convoluted, dunno who thought that logic up... Not me. Logic is to prevent some bugs and actually my comment "I don't believe it ever is." is totally wrong. ide_init_queue() is called for all drives on hwif. ie. failure scenario: 1st drive 48-bit: !rqsize -> max_sectors = 256, rqsize = 65536 2nd drive 28-bit: rqsize -> max_sectors = 65536 -> doh! so "< max_sectors" is really needed. It can look a bit saner: if (!hwif->rqsize) hwif->rqsize = hwif->addressing ? 65536 : 256; if (hwif->rqsize < max_sectors) max_sectors = hwif->rqsize; blk_queue_max_sectors(q, max_sectors); > > > > > Patch also misses updates for many uses of drive->addressing > > > > > (in ide.c, ide-io.c, icside.c, ide-tcq.c and even in ide-taskfile.c). > > > > > > > > Hmm bad grep, weird. > > > > > > ide.c: ide_dump_status(). this is an ugly one, but to me it already > > > looks correct. we are not throwing away any info by not reading the high > > > bits. > > > > It should check for rq_lba48(rq) || task->addressing. > > After taskfile IO switch it will be checking for task->addressing only. > > This is really ugly, but it has to look like that until you make the > global taskfile changes... Yep. > > > ide-io.c, ide-tcq.c, icside.c: indeed, missed these. > > > > > > > > Jens, I like the general idea of the patch, but it needs some more work. > > > > > Linus, please don't apply for now. > > > > > > > > Agree, I'll update the patch to suit your concerns tomorrow. > > > > > > Apart from the pdc202xx_old part, I think I've addressed all of your > > > concerns in this patch. > > > > Nope ;-), please move setting of hwif->rqsize from setup-pci.c to where > > it belongs, ide_init_queue() in ide-probe.c. > > So how's this? Looks good. Now test/review it for some time, we don't want any bugs to slip in. :-) -- Bartlomiej - 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/