Messages in this thread | | | Date | Wed, 7 Oct 2020 14:24:18 +0200 | From | Christoph Hellwig <> | Subject | Re: [PATCH 8/8] WIP: add a dma_alloc_contiguous API |
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On Wed, Oct 07, 2020 at 02:21:43PM +0200, Tomasz Figa wrote: > My initial feeling is that it should work, but we'll give you a > definitive answer once we prototype it. :) > > We might actually give it a try in the USB HCD subsystem as well, to > implement usb_alloc_noncoherent(), as an optimization for drivers > which have to perform multiple random accesses to the URB buffers. I > think you might recall discussing this by the way of the pwc and > uvcvideo camera drivers.
Yes. I guess for usb the dma_alloc_noncoherent as-is in linux-next might be better. So if you have the cycles please prototype it either way, although for that we'd also need at least a mmap_noncoherent method, and probaby a get_sgtable_noncoherent one.
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