Date: Mon, 23 Mar 2009 18:16:32 -0400 From: Justin Hibbits <jrh29@alumni.cwru.edu> To: Nathan Whitehorn <nwhitehorn@freebsd.org> Cc: freebsd-ppc@freebsd.org Subject: Re: Apple ATA DMA problems with ATAPI Message-ID: <20090323221632.GA1239@narn.knownspace> In-Reply-To: <alpine.BSF.2.00.0903221941130.18715@banshee.munuc.org> References: <20090322180638.GA3708@narn.knownspace> <8B9483E9-D6D4-441E-9202-31FA34F5DA98@mac.com> <20090322215406.GA1257@narn.knownspace> <alpine.BSF.2.00.0903221941130.18715@banshee.munuc.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sun, Mar 22, 2009 at 07:43:44PM -0500, Nathan Whitehorn wrote: > > > On Sun, 22 Mar 2009, Justin Hibbits wrote: > > > On Sun, Mar 22, 2009 at 01:41:18PM -0700, Marcel Moolenaar wrote: > >> > >> On Mar 22, 2009, at 11:06 AM, Justin Hibbits wrote: > >> > >>> Well, it seems I was bitten by the ATA DMA problems from a few > >>> months back. > >> > >> Try disabling DMA for atapi in /boot/loader.conf and enable > >> it in /etc/sysctl.conf. For some reason, on my Mac Mini at > >> least, it helps to first program PIO and then program *DMA. > >> > >> YMMV, > >> > >> -- > >> Marcel Moolenaar > >> xcllnt@mac.com > >> > >> > >> > > > > It appears hw.ata.atapi_dma is a read-only tunable, so /etc/sysctl.conf has no > > effect on it, and only throws a warning about being unable to change it. It's > > working sufficiently as PIO, though. > > > > So it looks like this issue is limited to ATAPI devices, and as a result I > have one more stab in the dark. Apparently at least some of these > controllers die if you try to give them an ATAPI command with a length > that is not divisible by 16. I have a patch at > http://people.freebsd.org/~nwhitehorn/ata-alignment.diff that converts > such commands to PIO. Could you see if it works? > > If this fails, I'll apply a sledgehammer and force all ATAPI devices on > Apple controllers to PIO. > -Nathan Unfortunately, that seems to have failed as well. I rebooted, and at the boot prompt set hw.ata.atapi_dma=1, and it had the same problem. Guess I'm out of luck for DMA on ATAPI. - Justin
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20090323221632.GA1239>