On Thursday 15 November 2012, Rob Clark wrote: > > I still haven't heard a conclusive argument why we need to use get_user() > > rather than copy_from_user() in the DRM code. Is this about a fast path > > where you want to shave off a few cycles for each call, or does this > > simplify the code structure, or something else? > > well, it is mostly because it seemed like a good idea to first try to > solve the root issue, rather than having to fix things up in each > driver when someone from x86-world introduces a 64b get_user().. As pointed out by hpa earlier, x86-32 doesn't have a 64b get_user either. I don't think we have a lot of drivers that are used only on 64-bit x86 and on 32-bit ARM but not on 32-bit x86. > There are some other arch's that don't have 64b get_user(), but I > don't think any that have any DRM drivers. If 64b get_user() is > really not intended to be supported by all archs, it is better to > remove it from x86 and the other arch's that do currently support it, > rather than making it possible to write drivers that are broken on > some archs. The majority of architectures we support have PCI and should be able to build the regular (radeon, nouveau, MGA, VIA, ...) DRM drivers AFAICT. Arnd _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
