On Wednesday 18 May 2016 17:37:40 Sricharan wrote: > > > >These comments are completely useless. What is the specific race > >that you are protecting against, and why are the implicit barriers > >not sufficient here? Please find a better way to document what > >is going on. > > > > The reason for doing this was, when the tlb maintenance ops are called > by io-pgtable functions, it expects that the tlb_range ops is complete > only after the tlb_sync callback is called. Previously we were using > writel and the sync in that case was dummy. Also previously every register > configuration write was done using writel, which was an overkill. So now > we do all the writes with writel_relaxed and a barrier in the end. I will > change the documentation for this. If you need the barrier after the write, it probably was already faulty before, because writel only implies a barrier before the store, not after. Of course all the barriers likely made the whole process so slow that you never hit that race in the end. Arnd -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
