Re: PDA Suspend SA1100

From: eric miao
Date: Thu Oct 18 2007 - 20:56:30 EST


On 10/19/07, Kristoffer Ericson <kristoffer.ericson@xxxxxxxxx> wrote:
> Greetings,
>
> I've been trying to implement proper suspend on my jornada 720 machine. But as far as I can see it never reaches
> the sa11x0_suspend code.
>
> I've linked power button event to produce APM_SUSPEND and I can see that it says "Stopping TASKS ======". It then
> blanks screen but keeps LCD powerd. I know it goes into resume again since removing backlight code in resume function
> effectivly turns off the LCD.
>
> Im assuming that it tries to suspend but fails at some point and tries to return into normal operations?
> Exactly what is needed to get the suspend procedure happy? Does every driver need to have suspend/resume code?

I don't think so. Unless a driver feels it necessary to take some
action, no suspend/resume
will not cause the whole system to fail. However,

1) if any driver suspend code returns error, the whole procedure will stop
2) and instable wake-up source (like glitch on wake-up GPIO pin) or
incorrect setting (like
wake up from RTC but set the interval to be 0) will also cause the
immediate resume

check "sa11x0_suspend" print out won't work since the console has already been
suspended, try DISABLE_CONSOLE_SUSPEND or other ways

- eric

>
> Best wishes
> Kristoffer Ericson
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