Bug#504391: Please enable CONFIG_MMC_UNSAFE_RESUME

[Moritz Muehlenhoff <jmm@inutil.org>]

severity 504391 wishlist
tags 504391 wontfix
thanks

On Mon, Nov 03, 2008 at 11:21:15AM +0000, Ross Burton wrote:
> Package: linux-image-2.6.26-1-686
> Version: 2.6.26-9
> Severity: normal
> 
> At present if I suspend and resume with a SD card inserted, the MMC driver
> crashes.  There is an "unsafe" option which can be enabled to fix this:
> CONFIG_MMC_UNSAFE_RESUME.  I have no idea why enabling this is considered
> unsafe, it took me several failed suspends (and the resulting data loss) to
> discover that the cause was a mounted SD card.

The Kconfig description explicitly describes this as a potentially
harmful option:

config MMC_UNSAFE_RESUME
        bool "Allow unsafe resume (DANGEROUS)"
        help
          If you say Y here, the MMC layer will assume that all cards
          stayed in their respective slots during the suspend. The
          normal behaviour is to remove them at suspend and
          redetecting them at resume. Breaking this assumption will
          in most cases result in data corruption.

          This option is usually just for embedded systems which use
          a MMC/SD card for rootfs. Most people should say N here.

Marking as wontfix, you should rather unplug your MMC card before
suspending.

But maybe you can file bugs against hibernate and graphical suspend
frontends to warn users if a plugged-in MMC card is detected.

Cheers,
        Moritz