On Tue, Jul 15, 2008 at 11:16:14AM -0500, Kumar Gala wrote: > > On Jun 6, 2008, at 2:24 PM, Anton Vorontsov wrote: > >> This patch adds suspend (standby, not suspend-to-ram) support for >> MPC86xx >> processors. >> >> In standby mode MPC86xx is able to wakeup only upon external >> interrupts >> (including sreset). >> >> Signed-off-by: Scott Wood <[EMAIL PROTECTED]> >> Signed-off-by: Jason Jin <[EMAIL PROTECTED]> >> Signed-off-by: Anton Vorontsov <[EMAIL PROTECTED]> >> --- >> arch/powerpc/Kconfig | 2 +- >> arch/powerpc/platforms/86xx/Makefile | 1 + >> arch/powerpc/platforms/86xx/mpc86xx_suspend.c | 92 ++++++++++++++++ >> +++++++++ >> 3 files changed, 94 insertions(+), 1 deletions(-) >> create mode 100644 arch/powerpc/platforms/86xx/mpc86xx_suspend.c > > I'd like to understand how much PM support these patches really add w/ > regards to the work Scott's done for 83xx PM.
This support provides "sleep" mode, i.e. almost all internal core functions are off, some peripherals could be turned off, but sysclk must be preserved. Upon wakeup CPU continues execution where it was put to sleep. This is also called standby mode. This patch does not implement "deep sleep" (suspend-to-ram) mode yet. Deep sleep can save more power: CPU can be turned off completely (except SDRAM -- it must still receive refresh cycles). But deep sleep is also more tricky to implement.. During deep sleep CPU losing all track of execution and state, thus upon wakeup CPU starts execution of the firmware, so the firmware should be also aware of deep sleep capability. -- Anton Vorontsov email: [EMAIL PROTECTED] irc://irc.freenode.net/bd2 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
