--- zzzz-none-000/linux-3.10.107/Documentation/power/swsusp.txt	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/Documentation/power/swsusp.txt	2021-02-04 17:41:59.000000000 +0000
@@ -50,6 +50,19 @@
 
 before suspend (it is limited to 500 MB by default).
 
+. The resume process checks for the presence of the resume device,
+if found, it then checks the contents for the hibernation image signature.
+If both are found, it resumes the hibernation image.
+
+. The resume process may be triggered in two ways:
+  1) During lateinit:  If resume=/dev/your_swap_partition is specified on
+     the kernel command line, lateinit runs the resume process.  If the
+     resume device has not been probed yet, the resume process fails and
+     bootup continues.
+  2) Manually from an initrd or initramfs:  May be run from
+     the init script by using the /sys/power/resume file.  It is vital
+     that this be done prior to remounting any filesystems (even as
+     read-only) otherwise data may be corrupted.
 
 Article about goals and implementation of Software Suspend for Linux
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -207,7 +220,10 @@
 
 A: Try running
 
-cat `cat /proc/[0-9]*/maps | grep / | sed 's:.* /:/:' | sort -u` > /dev/null
+cat /proc/[0-9]*/maps | grep / | sed 's:.* /:/:' | sort -u | while read file
+do
+  test -f "$file" && cat "$file" > /dev/null
+done
 
 after resume. swapoff -a; swapon -a may also be useful.
 
@@ -326,7 +342,7 @@
 disk drivers (especially SATA)?
 
 A: Well, it can be done, load the drivers, then do echo into
-/sys/power/disk/resume file from initrd. Be sure not to mount
+/sys/power/resume file from initrd. Be sure not to mount
 anything, not even read-only mount, or you are going to lose your
 data.
 
@@ -394,8 +410,17 @@
 
 Q: Can I suspend-to-disk using a swap partition under LVM?
 
-A: No. You can suspend successfully, but you'll not be able to
-resume. uswsusp should be able to work with LVM. See suspend.sf.net.
+A: Yes and No.  You can suspend successfully, but the kernel will not be able
+to resume on its own.  You need an initramfs that can recognize the resume
+situation, activate the logical volume containing the swap volume (but not
+touch any filesystems!), and eventually call
+
+echo -n "$major:$minor" > /sys/power/resume
+
+where $major and $minor are the respective major and minor device numbers of
+the swap volume.
+
+uswsusp works with LVM, too.  See http://suspend.sourceforge.net/
 
 Q: I upgraded the kernel from 2.6.15 to 2.6.16. Both kernels were
 compiled with the similar configuration files. Anyway I found that