Dear Arnd Bergmann, On Thu, 13 Nov 2014 11:53:19 +0100, Arnd Bergmann wrote: > > What do you think? > > IIRC there is still an unsolved problem on mach-keystone that is somewhat > related, they also have to change the page tables and the current method > appears to be racy. Once that is solved, you might be able to do 2. So maybe we need to invest time on this. I'll see how critical it is for us to have HW I/O coherency working on non-SMP configurations, and therefore if we can spend some time to work on this topic. > The approach I had in mind was much simpler, introducing a compile-time > option that hardcodes the behavior you need for Armada-370 when set, > knowing that you should not set that on any kernel that is supposed to > run on other platforms. Yes, I understood it was a compile-time option. Actually, switching to the write-allocate cache policy, and on SoCs that support it, to shareable pages, will continue to work on other platforms. So it does not break them, even though it might maybe cause some performance penalties (even though I'm not even sure that it would be the case). So it's not completely incompatible with doing a multi-platform kernel. Best regards, Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html