On 01/22/2013 01:46 PM, Tom Warren wrote: > 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?
I think that makes sense, yes. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot