From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: Why toggle_bounce only for disks? Date: Fri, 19 Aug 2005 12:21:33 +0200 Message-ID: <20050819102132.GM6273@suse.de> References: <20050806235615.GK3505@roadwarrior.mcmartin.ca> <58cb370e05081903073d9a2b73@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from ns.virtualhost.dk ([195.184.98.160]:432 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S932615AbVHSKTN (ORCPT ); Fri, 19 Aug 2005 06:19:13 -0400 Content-Disposition: inline In-Reply-To: <58cb370e05081903073d9a2b73@mail.gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Bartlomiej Zolnierkiewicz Cc: Kyle McMartin , linux-ide@vger.kernel.org, parisc-linux@lists.parisc-linux.org On Fri, Aug 19 2005, Bartlomiej Zolnierkiewicz wrote: > Hi, > > http://www.ussg.iu.edu/hypermail/linux/kernel/0209.1/1074.html > > Jens, is this still true?? It is, ide-cd would require changes to accept highmem pages. > > Ahoi, > > > > The following patch fixes a crash caused by attempting to bounce buffer > > when an IDE CD-ROM is used on a machine with an IO-MMU. [At least, this > > patch fixes things so I can use my IDE CD-ROM behind an ns87415 on a > > HP PA-RISC workstation.] > > > > Why was this only allowed for disks? Because not bouncing is a performance optimization and I only did the work on ide-cd to allow it. Your patch breaks ide-cd on highmem i386 machines, so it's not acceptable. Tells us more about this crash instead, I'm pretty sure you are working around another issue (your io-mmu code, is it hardware or software?) somehwere with this patch. > > --- a/drivers/ide/ide-lib.c 18 Jul 2005 18:46:30 -0000 > > +++ b/drivers/ide/ide-lib.c 6 Aug 2005 20:28:04 -0000 > > @@ -410,7 +410,7 @@ void ide_toggle_bounce(ide_drive_t *driv > > { > > u64 addr = BLK_BOUNCE_HIGH; /* dma64_addr_t */ > > > > - if (on && drive->media == ide_disk) { > > + if (on) { > > if (!PCI_DMA_BUS_IS_PHYS) > > addr = BLK_BOUNCE_ANY; > > else if (HWIF(drive)->pci_dev) > > > > Cheers, > > -- > > Kyle McMartin > -- Jens Axboe