On 19.03.2015 17:29, David Miller wrote: > From: Christian König <christian.koenig at amd.com> > Date: Thu, 19 Mar 2015 09:50:58 +0100 > >> In general I would say yes, but for this particular hardware it's a >> bit questionable to do so. >> >> For radeon hardware to work correctly the CPU access to the PCIE BARs >> should work even without using the specialized IO macros/functions, >> otherwise mapping VRAM CPU accessible isn't really possible. >> >> What's the background of the change? Some problems on a certain CPU >> platform? or just general cleanups? > It's an _iomem_ pointer, it's not a virtual address. > > Therefore it is illegal to dereference the pointer. > > The value is opaque and has values that only make sense when used > with the readb() et al. interfaces. > > This code is relying upon the fact that on x86 it happens to be > a virtual address, but this won't work on many other architectures.
In this case I'm perfectly fine with it and the patch is Reviewed-by: Christian König <christian.koenig at amd.com> Just wanted to make sure that you're not trying to get Radeon working on a platform which will never really support the necessary hardware features. Regards, Christian.
