2012-02-01 18:22:23

by Russell King - ARM Linux

[permalink] [raw]
Subject: Re: [PATCH v2] dmaengine: care sd_dma_address/len in dmaengine_prep_slave_single()

On Mon, Jan 30, 2012 at 05:13:30PM -0800, Kuninori Morimoto wrote:
> + sg_init_table(&sg, 1);
> + sg_set_page(&sg, pfn_to_page(PFN_DOWN(buf)),
> + len, offset_in_page(buf));

There's not much point setting this - the page/virtual address should
not be used by DMA engines as that may not reflect what's being requested
(especially if there's an IOMMU in the way.)