On Fri, Aug 02, 2019 at 10:57:00AM -0700, Gavin Li wrote: > usbfs mmap() looks like it was introduced for 4.6 in commit > f7d34b445abc, so it should probably be backported to 4.9 and onwards. > This issue has been present since the introduction of the feature. > > One sidenote: this patch will cause the following warning on x86 due > to dmap_mmap_coherent() trying to map normal memory in as uncached: > > x86/PAT: ... map pfn RAM range req uncached-minus for [mem > 0x77b000000-0x77b210fff], got write-back > > This warning is harmless, as x86 is DMA coherent and the memory gets > correctly mapped in as write-back. I will submit a patch to the DMA > mapping team to eliminate this warning. Let me know what the git commit id of that patch is, I will wait for it to hit the tree before adding this one. thanks, greg k-h
