WSOD on device

Nicolas Dufresne nicolas.dufresne at
Sun Mar 22 22:16:14 CET 2009

After more test,

I found that if I turn on GPS Zhone program (I don't think it's GPS
related, just that this program do update the screen) and let it go in
LCM sleep for a while I get funny screens. It's like if the Glamo keep
updating the display after FB_SHUTDOWN which might not be allowed by the

I think I'm stuck again on this issue. Spec speeks about waiting two
frames before SLEEP_OUT, but I have now idea how to do that with the
current design.

        The booster and display controller restart upon
        the termination of sleep mode. Display synchronization signals
        can be stopped in sleep mode. Ensure that display
        synchronization signals are supplied for a period of at least
        two frames before executing the Sleep-out command.
        Those signals are necessary to generate an idling state so that
        the internal circuits can start normally.
Also, this seems to be a task for the glamo driver. I found a fixme that
seems to be related:
        /* FIXME: once we have proper clock management in glamo-core,
         * we can determine if other units need MCLK1 or the PLL, and
         * disable it if not used. */

Without spec I don't think I of any help on that.

Best regards,

Le samedi 21 mars 2009 à 13:40 -0400, Nicolas Dufresne a écrit :
> Michael,
> I've implemented the changes describe in the specification part provided
> by Joerg. I tested this new version and I observe no regression. It
> would be nice if you could test it on your device.
> Nicolas

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