Stephen, On Fri, Jan 18, 2013 at 5:09 PM, Stephen Warren <swar...@wwwdotorg.org> wrote: > On 01/18/2013 05:01 PM, Stephen Warren wrote: >> On 01/18/2013 02:12 PM, Tom Warren wrote: >>> This provides SPL support for T114 boards - AVP early init, plus >>> CPU (A15) init/jump to main U-Boot. >> >>> +void powerup_cpus(void) >>> +{ >>> + debug("powerup_cpus entry\n"); >>> + >>> + /* Are we booting to the fast cluster? */ >>> + if (get_cluster_id() == 0) { >>> + debug("powerup_cpus entry: G cluster\n"); >>> + /* Power up the fast cluster rail partition */ >>> + power_partition(CRAIL, CRAILID); >>> + >>> + /* Power up the fast cluster non-CPU partition */ >>> + power_partition(C0NC, C0NCID); >>> + >>> + /* Power up the fast cluster CPU0 partition */ >>> + power_partition(CE0, CE0ID); >>> + } else { >>> + debug("powerup_cpus entry: LP cluster\n"); >>> + /* Power up the slow cluster non-CPU partition */ >>> + power_partition(C1NC, C1NCID); >>> + >>> + /* Power up the slow cluster CPU partition */ >>> + power_partition(CELP, CELPID); >>> + } >>> +} >> >> I strongly believe we should determine why that is needed rather than >> blindly upstreaming it. > > Thinking about this more, this makes even less sense. When Tegra boots, > code runs on the AVP. That code is U-Boot. U-Boot then boots the A15 > cores, and hence U-Boot is what decides whether to boot the LP or G > cluster; it doesn't follow some decision by some other SW since there is > no other SW. > > The only possible exception to this might be resume from some low-power > state where you want to restart the same A15 cluster as was running > prior to entering sleep. But that would require the flow controller > register read by get_cluster_id() to be in an always-on power domain. > I'm not sure if that's true or not. (If it isnt', presumably the > power-on state would always be static, hence there would be no need to > read the register).
I agree with your analysis. How about if I remove get_cluster_id(), and just set the power partitions for the fast cluster? _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot