Date: Wed, 16 Apr 2003 21:58:54 +0300 (EEST) From: Jarkko Santala <jake@iki.fi> To: Andrew Gallatin <gallatin@cs.duke.edu> Cc: freebsd-alpha@freebsd.org Subject: Re: problem with UDMA mode on XP1000 Message-ID: <20030416215733.R316@trillian.santala.org> In-Reply-To: <16029.36001.229632.79139@grasshopper.cs.duke.edu> References: <Pine.OSF.4.33.0304151146380.1028-100000@poptart.bithose.com> <16029.20850.720877.563791@grasshopper.cs.duke.edu> <16029.36001.229632.79139@grasshopper.cs.duke.edu>
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On Wed, 16 Apr 2003, Andrew Gallatin wrote: > > Jarkko Santala writes: > > I suppose no checking explains the performance. ;) But good to know > > anyway. Any reason why it gets enabled by default if its not safe? > > The ata code just enables the highest available mode by default. > > I'm no expert, but I don't think PIO is safe either. I think it just > stresses things so much less than DMA that its assumed to be safe. Drew How about adding all this into the alpha Hardware Notes? -jake -- Jarkko Santala <jake@iki.fi> http://www.iki.fi/~jake/ System Administrator 2001:670:83:f08::/64
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