Hi, I am doing this on A9, echo mem >/sys/power/state is right, will trigger kernel to sleep.
-jack On 7 March 2012 23:05, yang gqyang <hustgqy...@gmail.com> wrote: > dear all: > I am working on arm cortex a8 now, trying to implement "suspend to ram" > based on linux 3.0.8. > Before i start my work, the soc already support standby(the cpu is on wfi > state), so in order to implement "suspend to ram", i think i just need to > implement the arch-specific related api. The "suspend to ram" works like > this: > "echo mem > /sys/power/state" -> enter_state -> suspend_devices_and_enter > ->suspend_ops->enter(state) > Is that right? Do you think the "suspend to ram" can be realized in this > way? > In order to power off the cortex A8, i save all the writable > co-processor and all modes's state register set, and restore them when > resuming. > All the code seems work ok, because when I just does not power off the > cortex-A8 and jump to excute the resume code, the system works well. But, > when I power off the cpu, and wake up and excute resume code, the kernel > seem ok, but the busybox toolkit does not work proper, eg: "ls" can not > output the result through serial port. i add "printk statement" trying to > locate the reason, but at this time, the "ls" work fine. hence, i doubt > something must be corrupted after resume. > I have checked all the state register and co-processor, having not found > any exception, and I also compared all the dram data before power off and > after wake up, nothing have changed. Right now, I do not know what has > happened, and what should I do to locate the real problem to make the > busybox works ok. I also want to know does the linux kernel 3.0.8 support > "suspend to ram" like this: > "echo mem > /sys/power/state" -> enter_state -> suspend_devices_and_enter > ->suspend_ops->enter(state)? > Can anyone give me some suggestion? Any comment is welcome, thanks a lot. > > >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-pm" in >> the body of a message to majord...@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > > _______________________________________________ > linaro-dev mailing list > linaro-dev@lists.linaro.org > http://lists.linaro.org/mailman/listinfo/linaro-dev > >
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