From: Matteo Fortini <matteo.fortini@mta.it>
To: linux-ppc list <linuxppc-dev@ozlabs.org>
Subject: Re: MPC512x DMA to PCI dev
Date: Thu, 12 Mar 2009 11:51:25 +0100 [thread overview]
Message-ID: <49B8E92D.304@mta.it> (raw)
In-Reply-To: <49B7AA80.2030501@mta.it>
Ok,
I answer to myself, to whomever it may interest: the DMA controller to
use is the PCI_DMA controller, and not the generic DMA controller.
Right now, I'm trying to figure out if there's a generic PCI API I can
extend to talk to the PCI DMA controller.
Matteo Fortini ha scritto:
> Hi all,
> I'm trying to send some data through DMA from a memory buffer to a PCI
> video card VRAM.
>
> While I got that I need to alloc the src buffer through
> dma_alloc_coherent, I don't understand which address I should give as
> the dst address.
>
> I tried both the mapped hw address and an address received from
> pci_map_single, but even if the DMA transfer completes "correctly", I
> have the wrong data in the VRAM in the end.
>
> I read about all the PCI DMA manuals, but it seems they are for letting
> some external DMA device on the PCI bus read/write from/to the main memory.
>
> How do you do that?
>
> Thanks,
> Matteo
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-dev
>
>
prev parent reply other threads:[~2009-03-12 11:26 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-11 12:11 MPC512x DMA to PCI dev Matteo Fortini
2009-03-12 10:51 ` Matteo Fortini [this message]
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