Messages in this thread | | | Date | Thu, 13 Jul 2006 16:24:18 +0200 | From | Manuel Lauss <> | Subject | Re: Bugs in usb-skeleton.c??? :) |
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On Thu, Jul 13, 2006 at 05:10:20PM +0400, Sergej Pupykin wrote: > >> Does kmalloc always allocate pages that can be used in DMA? > > AvdV> normally yes. HOWEVER.... > > I use sh4 cpu...
on SH-4 traditionally the whole memory space is mapped all the time, so any space returned by kmalloc is DMA-able. (I don't know if this applies to the SH-4A core, too)
> AvdV> ..it is nicer to use the DMA allocation API (which internally may fall > AvdV> back to kmalloc etc), while kmalloc may work, it can be quite slow in > AvdV> how it's made to work. So it's just nicer to just use the DMA memory > AvdV> allocators... (see Documentation/DMA-API.txt file for a description of > AvdV> this)
agree
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