Re: Suspend and Hibernation Bugs

[Zachary Palmer <zep_bcache-J5qI5MFTcs8@public.gmane.org>]

It seems that installing linux-image-3.11-rc4-686-pae=3.11~rc4-1~exp1 
from Debian's experimental repository solved my problem.  :)  Thanks!

- Zach
> On Sun, Sep 01, 2013 at 02:10:11PM -0400, Zachary Palmer wrote:
>> Hello there.  I'm not sure if this is the appropriate venue, so
>> please let me know if this information should be somewhere else.  I
>> have configured a Debian 7.0 installation on a Dell Inspiron 17R SE
>> laptop to use a bcache root device.  The previous known working
>> configuration for the laptop was:
>>
>>      /dev/sda (1TB HDD)
>>          ...
>>          /dev/sda7 (used as LUKS encrypted volume)
>>              /dev/mapper/sda7_crypt (used as LVM PV)
>>                  /dev/vg0/home
>>                  /dev/vg0/root
>>                  ...
>>          /dev/sda8 (used as ext3 /boot)
>>
>> The new configuration is
>>
>>      /dev/sda (1TB HDD)
>>          ...
>>          /dev/sda7 (used as bcache backing device)
>>              /dev/bcache0 (used as LUKS encrypted volume)
>>                  /dev/mapper/bcache_crypt (used as LVM PV)
>>                      /dev/vg0/home
>>                      /dev/vg0/root
>>                      ...
>>          /dev/sda8 (used as ext3 /boot)
>>      /dev/sdb (32GB SSD)
>>          ...
>>          /dev/sdb3 (used as bcache caching device)
>>
>> In order to get things booting, I also:
>>
>>      * Installed a Linux 3.10 kernel from wheezy-backports
>> (3.10-0.bpo.2-686-pae)
>>      * Obtained a copy of the bcache-tools source from the git repo
>> and compiled it
>>      * Constructed a Debian package for bcache-tools using checkinstall
>>      * Because udev recognition wasn't enough at boot time, added a
>> script /etc/initramfs-tools/scripts/init-premount/z-bcache which
>> looks like this:
>>              #!/bin/sh -e
>>
>>              # ZEP - Added (2013-08-29) because some bcache devices
>> were not being detected
>>              #       at startup by udev.  This sloppy hack should do
>> the job.
>>
>>              PREREQS=""
>>
>>              prereqs() { echo "$PREREQS"; }
>>
>>              case "$1" in
>>                  prereqs)
>>                      prereqs
>>                      exit 0
>>                      ;;
>>              esac
>>
>>              . /scripts/functions
>>
>>              if [ -e '/sys/fs/bcache/register_quiet' ]; then
>>                  log_begin_msg "Scanning for bcache devices..."
>>                  for d in `ls /dev/sd*`; do
>>                      echo "$d" > /sys/fs/bcache/register_quiet
>> 2>/dev/null || true
>>                  done
>>                  log_end_msg "bcache device scan complete"
>>              else
>>                  log_warning_msg "/sys/fs/bcache/register_quiet not
>> found; not registering devices"
>>              fi
>>      * Executed update-initramfs -u -k all to get everything working
>>
>> My machine boots from /dev/sda8 and the initramfs has enough
>> machinery to get the root drive mounted.  I was thrilled until I
>> discovered that neither suspend nor hibernate seems to work; the
>> suspend process seizes up while suspending devices and never comes
>> back.  I booted the laptop from a custom Debian live disk using the
>> same kernel (3.10-0.bpo.2-686-pae) and performed a series of tests:
>>
>>      * When the bcache kernel module was not loaded, suspend to RAM
>> worked correctly.
>>      * When the bcache kernel module was loaded but no devices were
>> registered, suspend to RAM worked correctly.
>>      * When a single bcache device was registered using "echo
>> /dev/sda7 > /sys/fs/bcache/register; echo /dev/sdb3 >
>> /sys/fs/bcache/register", suspend to RAM failed to change the power
>> state of the machine.
>>      * With a /dev/bcache0 device in use as an encrypted volume,
>> running "echo freezer > /sys/power/pm_test; echo platform >
>> /sys/power/disk; echo disk > /sys/power/state" allows the machine to
>> awaken from the test correctly.
>>      * With a /dev/bcache0 device in use as an encrypted volume,
>> running "echo devices > /sys/power/pm_test; echo platform >
>> /sys/power/disk; echo disk > /sys/power/state" causes the machine to
>> hang.
>>
>> Has suspend/hibernate been tested with bcache?  Is it supported? I'm
>> trying to figure out if it's my specific laptop hardware causing the
>> issue or if bcache is somehow at fault.  (Clearly, I can get
>> suspend/hibernate back if I migrate back to using just my HDD, but
>> caching blocks in a fashion designed for SSDs seems like such a
>> lovely idea.)
> Suspend/resume works fine for me (sort of).  On 3.10.5 I saw some sort of bug
> with the freezer that went away if I disabled the Intel MEI driver (or just
> applied Kent's for-3.11 branch).  I don't recall if Kent ever submitted it for
> 3.10.
>
> --D
>