Messages in this thread | | | Date | Mon, 11 Jul 2022 12:39:21 +0200 | From | Christoph Hellwig <> | Subject | Re: [PATCH] swiotlb: ensure io_tlb_default_mem spinlock always initialised |
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On Mon, Jul 11, 2022 at 11:24:51AM +0100, Ben Dooks wrote: > On 11/07/2022 11:21, Christoph Hellwig wrote: >> On Mon, Jul 11, 2022 at 11:07:17AM +0100, Robin Murphy wrote: >>> If none of your peripherals should need SWIOTLB, then the fact that >>> you're ending up in swiotlb_map() at all is a clear sign that >>> something's wrong. Most likely someone's forgotten to set their DMA >>> masks correctly. >> >> Yes. > > Possibly, we had at least one driver which attempted to set a 32 bit > DMA mask which had to be removed as the DMA layer accepts this but > since there is no DMA32 memory the allocator then just fails. > > I expect the above may need to be a separate discussion(s) of how to > default the DMA mask and how to stop the implicit acceptance of setting > a 32-bit DMA mask.
No. Linux simply assumes you can do 32-bit DMA and this won't change. So we'll need to fix your platform to support swiotlb eventually.
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