On Sat, Feb 04, 2012 at 07:13:41PM -0800, Ben Widawsky wrote: > On 02/02/12 00:40, Daniel Vetter wrote: > >On Wed, Feb 01, 2012 at 09:30:57PM -0800, Ben Widawsky wrote: > >[...] > >>I'd also say it's not a bad idea to elaborate the assumption that we > >>never have less than 256MB of memory WARN_ON(dimm_c0 + dimm_c1 == 0). > > > >I'm pretty sure that we can't boot with 0mb of ram ;-) The other thing is > >that swizzling is a pure preformance optimization - if we enable it on > >setup where it's not required we'll only annoy the memory controller with > >less efficient access patterns. > > What I meant was, this value is still 0 in say, a system with 2 > 128MB DIMMs. Well, I have a feeling that 256mb is the smallest size for a ddr3 dimm. But I'm a bit too lazy to check that (and frankly wouldn't know where). Furthermore swizzling on gen6+ is afaics just a performance thing and should never affect correctness, so even if 128mb dimms exist I think we can just not care - performance isn't gonna be stellar anyway ;-) -Daniel -- Daniel Vetter Mail: daniel at ffwll.ch Mobile: +41 (0)79 365 57 48
