From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Sanka Piyaratna <cesanka@yahoo.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: PCIe device driver question
Date: Wed, 30 Jul 2008 16:47:18 +0100 [thread overview]
Message-ID: <20080730164718.1befdd07@lxorguk.ukuu.org.uk> (raw)
In-Reply-To: <125082.62307.qm@web31706.mail.mud.yahoo.com>
On Wed, 30 Jul 2008 09:00:58 -0700 (PDT)
Sanka Piyaratna <cesanka@yahoo.com> wrote:
> Hi,
>
> I am currently developing a PCIe data capture card hardware and the
> device drivers to drive this. I have implemented DMA on the data
> capture and the scatter-gather DMA is implemented in the hardware. I
> am testing this in an X86_64 architecture machine with 4 GB of RAM. I
> am able to successfully dma data into any memory (dma) address >
> 0x0000_0001_0000_0000. However, my problem is to dma data to any
> address less than this. When I try to DMA data to an address less than
> 0x0000_0001_0000_0000, the hardware device hangs indicating that the
> address does not exist.
Assuming the failures are in the range 640K-1MB then I would imagine your
bridge doesn't permit transfers via DMA to the ISA hole.
next prev parent reply other threads:[~2008-07-30 16:04 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-30 16:00 Sanka Piyaratna
2008-07-30 15:47 ` Alan Cox [this message]
2008-07-30 16:09 Sanka Piyaratna
2008-07-30 16:51 ` V.Radhakrishnan
2008-07-30 16:55 ` Alan Cox
[not found] <fa.PmBLCqOb4Xo53y3W9hAdnsU50Og@ifi.uio.no>
[not found] ` <fa.42mxuHHJP7XQmYeyxNoEC/NFUHA@ifi.uio.no>
2008-07-30 19:21 ` Robert Hancock
2008-07-31 13:11 ` V.Radhakrishnan
2008-07-31 17:37 ` Robert Hancock
2008-07-31 18:47 ` V.Radhakrishnan
2008-07-31 18:52 ` Robert Hancock
2008-07-31 20:47 ` V.Radhakrishnan
[not found] <fa.+kKL98uFtvbcX3ymh2HlJuUDVwY@ifi.uio.no>
2008-07-30 19:24 ` Robert Hancock
2008-07-30 22:55 Sanka Piyaratna
2008-07-31 8:44 ` Robert Hancock
2008-07-31 9:58 Sanka Piyaratna
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