Hung kernel on SD writeback while suspending to RAM

[Eric Bénard]

Hi,

Le 15/06/2010 09:58, Alex Gonzalez a écrit :
> I am looking into suspend to RAM on a Freescale MX51 running a 2.6.31
> kernel. The
> system suspends and resumes OK except when an SD card is mounted.
>
> What happens then is that it finds a page which is being written to disk
> (writeback flag is set), so it waits forever in uninterruptible state
> for the write to finish, which never happens.
>
> I was expecting the filesystem sync previous to the tasks freezing to
> have written all page caches to disk.
>
> Any suggestion as to how to debug this forward?
>
I think you need to enable
[ ] Assume MMC/SD cards are non-removable (DANGEROUS)
in order to be able to suspend / resume a mounted SDCard.

Eric