Bug#643301: linux-image-3.0.0-1-rt-amd64: Suspend to ram hangs

[Jonathan Nieder <jrnieder@gmail.com>]

Hi John,

John O'Hagan wrote:

> I run daily-updated testing on an HP Mini 5102 with N10 graphics card (uses
> i915) running XFCE4.8. When 3.0.0-1 kernel came in I installed both RT and non-
> RT versions. On non-RT version, both suspend-to-ram and resume work as
> expected. On RT kernel they work with only XFCE desktop running, however if
> other programs are running as well (I've tried Chromium and Sylpheed), when
> suspend is attempted, the screen goes black, fan runs high, and keyboard
> becomes unresponsive, requiring a hard shutdown every time. I've reproduced
> this about a dozen times.
>
> Nothing unusual in pm-suspend log that I could see.

Excellent detective work; thank you.  It would be nice to pin this on
a particular driver, if possible.  So:

 1. Can you reproduce it with suspend-to-disk, too?  (That means
    "echo disk >/sys/power/state".)

 2. Can you reproduce it without the graphics driver loaded (e.g., if you
    can reproduce it by inducing some network activity with programs like
    "w3m" from a terminal in X, can you do the same by booting with "single"
    on the kernel command line and trying the same in the console)?  I
    realize this might be hard to check.

 3. Since hey, one can be lucky sometimes: is it possible to catch the
    failure as it happens, for example by not suspending the console and
    suspending everything else?  See

    https://raw.github.com/torvalds/linux/master/Documentation/power/basic-pm-debugging.txt
    https://raw.github.com/torvalds/linux/master/Documentation/networking/netconsole.txt

    (or the analagously named files in the linux-doc-3.0.0 package) for
    hints in that direction.

 4. Does Alt+Sysrq work in the broken state?  If so, the following
    could be useful.

     1. Enable debugging with the sysrq key (see Documentation/sysrq.txt):

	echo 1 >/proc/sys/kernel/sysrq; # or 446

     2. Suspend or hibernate, without suspending the console.
     3. Press Alt+Sysrq + 'w' to show blocked tasks.
        Or press Alt+Sysrq + 'c' to trigger a crash dump.

> ** Tainted: C (1024)
>  * Module from drivers/staging has been loaded.
[...]
> [    8.960305] brcmutil: module is from the staging directory, the quality is unknown, you have been warned.
> [    9.019973] brcmsmac: module is from the staging directory, the quality is unknown, you have been warned.

Is it possible to reproduce this without brcmsmac?  E.g., does the b43
driver support your card (I haven't checked)?

Hope that helps,
Jonathan