Domen Puncer wrote: > U-Boot part of Lite5200b low power mode support. > Puts SDRAM out of self-refresh and transfers control to > address saved at physical 0x0. >
Hi Domen, As I understand while waking up from the low-power mode the machine is effectively powering on, similarly to the cold reset, so U-Boot runs from the beginning as usual, but after the SDRAM controller has been initialised we detect the wakeup and teleport to the saved DRAM address. Since in case of a wakeup from the low-power mode we skip everything in U-Boot that is happening past initdram(), please clarify the following: - are you sure there are no steps beyond init_func_ram()/board_init_f() that should be performed while waking up? For example: - are all timers settings properly re-stored? - wouldn't the host/PCI bridge need to be re-initialised and re-configured as part of the wakeup process? Did you happen to test some PCI devices and would they survive after wakeup from the the low-power mode? (A similar question would apply to the USB controller) Also, a more general question: isn't time base update required after the wakeup, specially if it's been a long sleep? kind regards, Rafal _______________________________________________ Linuxppc-embedded mailing list [email protected] https://ozlabs.org/mailman/listinfo/linuxppc-embedded
