Re: PM with rootfs on mmc?

[Len Brown <lenb@kernel.org>]

On Wed, 31 Dec 2008, Sriram V wrote:

> Hi,
>   I am trying to test pm on my platform/board.
>   I am using the latest linux kernel - 2.6.28-rc6
>   PM Support exists in my mmc driver and suspend and resume work fine.
> 
>   With rootfs mounted via NFS. I am able to do
>    $ echo -n mem > /sys/power/state
> 
>   The above works. It successfully calls suspend and resume of sdmmc driver.
> 
>   However, the same does not work if i have mounted the SDMMC card
> with rootfs on NFS.
> 
>   The kernel hangs, when i try to do
>      $ echo -n mem > /sys/power/state
> 
>  In this case suspend and resume functions of the driver are not called
>  at all. (I gave a couple of debug prints at the beginning of suspend and resume
>  and they didnot get print)
> 
>  Same behaviour is observed when i boot out of SDMMC card. Suspend/Resume
>  dont work. The kernel hangs.
> 
> I get the messages in both case when i suspend-to-ram.
> 
> PM: Syncing filesystems ... done.
> Freezing user space processes ... (elapsed 0.00 seconds) done.
> Freezing remaining freezable tasks ... (elapsed 0.00 seconds) done.
> Suspending console(s) (use no_console_suspend to debug)
> 
> 
> I am not sure if this has to do with SD/MMC driver or something else.

What do you seen when you boot with "no_console_suspend"

You may also want to check out
Documentation/power/basic-pm-debugging.txt"

cheers,
-- Len Brown, Intel Open Source Technology Center