From: Matteo Fortini <matteo.fortini@mta.it>
To: linux-ppc list <linuxppc-dev@ozlabs.org>
Subject: MPC512x DMA to PCI dev
Date: Wed, 11 Mar 2009 13:11:44 +0100 [thread overview]
Message-ID: <49B7AA80.2030501@mta.it> (raw)
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
next reply other threads:[~2009-03-11 12:43 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-11 12:11 Matteo Fortini [this message]
2009-03-12 10:51 ` MPC512x DMA to PCI dev Matteo Fortini
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