From owner-freebsd-questions  Tue Mar 27 21:40:27 2001
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Reply-To: leisner@rochester.rr.com
To: Tim Joseph <tim@weeble.org.uk>
Cc: freebsd-questions@FreeBSD.ORG, leisner@rochester.rr.com
Subject: Re: U/DMA on FSBD 4.x 
In-reply-to: Your message of "Sun, 25 Mar 2001 11:48:42 +0100."
             <Pine.BSF.4.33.0103251130220.69306-100000@doubtful.weeble.foo.uk> 
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Date: Wed, 28 Mar 2001 00:40:21 -0500
From: "Marty Leisner" <leisner@rochester.rr.com>
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I've been using DMA with linux with several years.

Did you play around with hdparm and exercise the options you were
warned as "dangerous?"

Did you discuss your problems with the linux IDE maintainers?


Marty Leisner


Tim Joseph <tim@weeble.org.uk> writes  on Sun, 25 Mar 2001 11:48:42 +0100
     > Hi,
     > 
     > I've had some bad experiences with DMA and UDMA/33 under Linux (2.2.x
     > kernels). In the best case the controller reset and switched off DMA, in
     > the worst I've had my whole hardrive hosed.
     > 
     > Does anyone have any experience on the relative maturity of the DMA code
     > in FBSD 4.x-stable versus what was in Linux (which to be, fair was
     > advertised as experiental).
     > 
     > How do I go about enabling DMA or UDMA on my box?
     > 
     > Is U/DMA "safe" under FBSD? Are there any particular chipset/harddrive
     > combos to watch out for?
     > 
     > I'm running a K6-2/350MHz, 256MB PC100 SDRAM, MS-5169 (ATX AL9)  mobo,
     > Aladdin 5 M1531/M1543 chipset, IBM Deskstar IDE (UDMA/33) HDD. My dmesg
     > has rotated so I can't show you the kernel boot messages at the mo, but 
I
     > can reboot and dig it up if needed.
     > 
     > Thanks.
     > 
     > From,
     > 
     > Tim
     > 
     > 
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