Date: Thu, 6 Jul 2000 23:18:05 -0700 (PDT) From: Matthew Jacob <mjacob@feral.com> To: Kelly Yancey <kbyanc@posi.net> Cc: "Kenneth D. Merry" <ken@kdm.org>, Zhihui Zhang <zzhang@cs.binghamton.edu>, freebsd-hackers@FreeBSD.ORG Subject: Re: Max DMA size Message-ID: <Pine.BSF.4.10.10007062317320.21180-100000@beppo.feral.com> In-Reply-To: <Pine.BSF.4.21.0007062239260.21752-100000@gateway.posi.net>
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> Hmm. My knowledge may be a bit dated in this matter, but as I recall the > 8237 DMA controller standard on PCs only supports DMA requests up to 128k (and > then only on the upper 4 DMA channels). The low 4 DMA channels were > byte-granular and could only transfer 64k. Am I correct in assuming from this > discussion that the state of affairs is somewhat different nowadays? Uh, yeah. Standard PCI h/w usually has 32 bit dma engines, and a lot have 64 bit. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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