Date: Tue, 25 Aug 1998 20:52:32 -0400 From: john hood <cgull@owl.org> To: Parag Patel <parag@cgt.com> Cc: Joe Gleason <freebsd.list@bug.tasam.com>, freebsd-hardware@FreeBSD.ORG Subject: Re: UDMA Support Message-ID: <19980825205232.19718@owl.org> In-Reply-To: <199808252152.OAA04488@pinhead.parag.codegen.com>; from Parag Patel on Tue, Aug 25, 1998 at 02:52:34PM -0700 References: <19980825021026.12093@owl.org> <199808252152.OAA04488@pinhead.parag.codegen.com>
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On Tue, Aug 25, 1998 at 02:52:34PM -0700, Parag Patel wrote: > > >-current supports DMA, but not Ultra DMA, which is faster and has > >CRC error checking. > > That's odd - I thought it supported UDMA. Perhaps you meant -stable? Urrgh, I should know better, I wrote it, after all :) What I really should have said is that the error-checking features of UDMA (which are somewhat important) aren't supported properly. The timing setup and enabling of UDMA is supported. So UDMA is partly supported. -stable hasn't got any DMA support, and nobody's hurrying to implement it, though I keep telling myself I'll spend the while doing the backport sometime... > My reading of the file /sys/pci/ide_pci.c suggests that 3.0 does support UDMA for PCI-IDE chips. I made some additions to it to support the newer CMD646U2 PCI-UIDE chip but they haven't made it into the source tree yet (I don't know who the new owner of this code is). The individual chip dmainit routines are supposed to turn on udma mode if possible. Soren's more or less in charge of the ATA/ATAPI code. I wrote the ATA DMA code, so people ask me about it. I've submitted the code you sent me, along with a bunch of other updates, to Soren, who has been...sitting on it :) Soon, soon. --jh -- Mr. Belliveau said, "the difference was the wise, John Hood, cgull intelligent look on the face of the cow." He was @ *so* right. --Ofer Inbar owl.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message
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