On 2019-01-21 5:30 p.m., Ard Biesheuvel wrote: > On Mon, 21 Jan 2019 at 17:22, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > >> Until that happens we should just change the driver ifdefs to default >> the hacks to off and only enable them on setups where we 100% >> positively know that they actually work. And document that fact >> in big fat comments. > > Well, as I mentioned in my commit log as well, if we default to off > unless CONFIG_X86, we may break working setups on MIPS and Power where > the device is in fact non-cache coherent, and relies on this > 'optimization' to get things working. FWIW, the amdgpu driver doesn't rely on non-snooped transfers for correct basic operation (the scenario Christian brought up is a very specialized use-case), so that shouldn't be an issue. -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
