Date: Thu, 17 Jun 1999 16:29:11 -0700 (PDT) From: mike@hyperreal.org To: bright@rush.net (Alfred Perlstein) Cc: freebsd-questions@freebsd.org Subject: Re: Optimizing IDE performance revisited Message-ID: <19990617232911.29625.qmail@hyperreal.org> In-Reply-To: <Pine.BSF.3.96.990617151259.14320q-100000@cygnus.rush.net> from Alfred Perlstein at "Jun 17, 1999 03:16:46 pm"
next in thread | previous in thread | raw e-mail | index | archive | help
Alfred Perlstein wrote:
> > Is there something else that I need to configure in the kernel to enable PIO
> > or DMA?
>
> yes, set your IDE flags to 0xa0ffa0ff , or some subset of that, check
> the LINT kernel config file, some machines that don't support DMA will
> hang if DMA is enabled, so double check it.
Oh, not really understanding what bus-mastering DMA is, I didn't realize
that this flag was referring to the same kind of DMA (perhaps if it had
made some reference to DMA modes..)
0x2000 Probe for and use the bus-mastering DMA capabilities of
modern PCI chipsets.
So, 0xb0ffb0ff as I have is fine. (The extra 0x1000 = use LBA). Looking at
the driver source, it looks like a "wdc0: DMA failure" message will appear
if something goes wrong.
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?19990617232911.29625.qmail>