Hi Johansson, Thanks for your response
在 2009-09-10四的 11:09 +0200，Kenneth Johansson写道： > On Wed, 2009-09-09 at 13:43 -0500, Scott Wood wrote: > > On Wed, Sep 09, 2009 at 01:16:07PM +0200, Kenneth Johansson wrote: > > > On Tue, 2009-09-08 at 13:48 +0800, Li Tao-B22598 wrote: > > > > Dear all, > > > > > > > > I have a problem in MPC5121 sleep mode. As you know MPC5121 use e300c4 > > > > core. When I make the e300c4 core into sleep mode, it will return to > > > > full power mode when the“decrementer interrupt” occurred. > > > > > > > > But in the e300 core reference manual said that the “decrementer > > > > interrupt”have no effect when e300 core in sleep mode, because the > > > > time > > > > base and decrementer are disabled while the core is in sleep mode. > > > > Can anybody explain about this procedure ? > > > > I'm not specifically familiar with MPC5121, but I'll answer from the > > perspective of MPC83xx which has a similar core: > > > > The decrementer stops ticking when the core goes to sleep. However, if a > > decrementer was already pending (but masked with MSR[EE]) before you > > enter sleep mode, it will cause a wakeup. > > > > To avoid this, the decrementer is set to a very large value prior to and > > after disabling interrupts. See generic_suspend_disable_irqs() in > > arch/powerpc/kernel/time.c. Is this not happening for you? Which kernel > > version are you using, and what mechanism are you using to go to sleep? > > > > > I'm a bit irritated that it's not as the "solution" can mean hardware > > > changes an thus it's potentially expensive. > > > > What sort of hardware changes? > > I don't want to spread missinformation but this procedure has helped on > the ads5121 rev3 and two custom boards. > > the gpio 28,29,30 needs to be low and gpio31 needs to be hi. regardless > of what is used as wakeup source when the device enters deep sleep > otherwise you end up in some sort of meta state where you might not wake > up on anything and you have this 42 second auto wakeup from the > decrementer. I use ads5121 rev4.1 board, the gpio 28,29,30 is low and gpio31 is high. I find that the RTC is fail too, when I use hwclock -f /dev/rtc0 cmd, it was always "Wed Dec 31 23:59:59 1969 0.000000 seconds". I measured the the RTC oscillator is 32.768 kHz, and the VBAT_RTC is 4.2v. I have no idea about why RTC is fail. > > Other weired states has also been observed. the PMC module is a bit > tempremental in this chip. > > > _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
