Messages in this thread | | | Date | Wed, 25 Apr 2012 16:18:23 +0200 | From | Lars-Peter Clausen <> | Subject | Re: [PATCH v2] dmaengine: care sd_dma_address/len in dmaengine_prep_slave_single() |
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On 02/01/2012 07:22 PM, Russell King - ARM Linux wrote: > 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.)
I was just looking at this again and there are actually quite a few dma engine drivers which use sg->length and sg_phys(sg). I guess these would break if the sg_set_page was to be removed. Should these drivers be changed to use sg_dma_len and sg_dma_address?
Thanks - Lars
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