pxa:spitz_pm.c: commit b6eede11 breaks spitz resume under certain conditions.

[Eric Miao]

On Fri, Sep 21, 2012 at 3:29 AM, Marko Katić <dromede at gmail.com> wrote:
> Hi Eric,
>
> ========================================================
> commit b6eede112673678f8a7a1680d6ad12245443829d
> Author: Eric Miao <eric.y.miao at gmail.com>
> Date:   Mon Jan 11 16:17:25 2010 +0800
>
>     [ARM] pxa/spitz: use generic GPIO API and remove pxa_gpio_mode()
>
>     REVISIT: change to GPIO18 is ugly, need to make sure whether that's
>     really necessary - GPIO18_RDY as an VLIO input signal - we don't
>     normally need to do such kind of trick during low power mode.
>
> =========================================================
>
> This GPIO18 change breaks spitz resume.
> Spitz will fail to resume from STR under these conditions:
>
> 1) If the AC plug is powered and plugged in, and if you suspend the machine,
>     the machine will not be able to resume if you remove the AC plug while the
>    device is suspended.
>
> 2) If you connect the machine to a powered AC plug while the device is
> suspended,
>     the machine will not be able to resume.
>
> If i comment out the call to pxa2xx_mfp_config in spitz_postsuspend(),
> my machine will
> properly resume under abovementioned conditions.
>
> If i understand correctly, spitz_postsuspend () configures GPIO 18
> to alternate mode 1 - RDY. However, I have no idea what RDY means or
> what this GPIO is used for.
>
> Eric can you please explain what's happening here?

I believe that was derived from the legacy code, so if you think it's
a bug and can get a proper fix, just go with it. Note, however, if the
code affects poodle/corgi, you may take another look and make sure
it doesn't break the rest ones.