On Sat, Mar 10, 2018 at 10:20:23AM -0800, Andy Lutomirski wrote: >>> Perhaps the easy answer is to change the fatal is-pat-enabled check to just >>> a warning like "you have PAT enabled, so wc is disabled for the framebuffer. >>> if you want wc, use the nopat parameter"? >> >> I like this idea more and more. I haven't experience any problems running >> with PAT-enabled and no write-combining on the framebuffer. Any objections? >> > > None from me. > > However, since you have the hardware, you could see if you can use the > change_page_attr machinery to change the memory type on the framebuffer once > you figure out where it is.
I am certainly willing to try this, but my understanding of the goal of the changes that disabled ivtvfb originally is that it was trying to hide the architecture-specific memory management from the driver. Wouldn't (figuring out a way to) expose x86/mm/pageattr internals to the driver be doing the opposite? (or maybe I misunderstand your suggestion) - Nick