On Tue, 21 Sep 2010 16:24:10 -0500 Timur Tabi <timur.t...@gmail.com> wrote:
> On Tue, Sep 21, 2010 at 7:55 AM, Kumar Gala <ga...@kernel.crashing.org> wrote: > > > > On Sep 21, 2010, at 5:57 AM, Li Yang wrote: > > > >> Signed-off-by: Li Yang <le...@freescale.com> > >> --- > > > > We really should have a sentence about how or why this works to address > > 36-bit addressing. > > For example, I would like to know which memory is going to be > allocated above 4GB. I don't know much about the kernel's async > library, but my understanding is that fsldma does not allocate any of > the memory buffers that it copies data to/from. This doesn't control allocation (it probably should with dma_alloc_coherent, though I don't see it in the code), it controls whether swiotlb will create a bounce buffer -- defeating the point of using DMA to accelerate a memcpy. -Scott _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
