[patch] swsusp: documentation updates

[patch] swsusp: documentation updates

[Pavel Machek]

This updates suspend-to-RAM documentation with new machines, and makes
message when processes can't be stopped little clearer. (In one case,
waiting longer actually did help).

Signed-off-by: Pavel Machek <pavel@suse.cz>

--- a/Documentation/power/video.txt
+++ b/Documentation/power/video.txt
@@ -104,6 +104,7 @@ HP NX7000			??? (*)
 HP Pavilion ZD7000		vbetool post needed, need open-source nv driver for X
 HP Omnibook XE3	athlon version	none (1)
 HP Omnibook XE3GC		none (1), video is S3 Savage/IX-MV
+HP Omnibook 5150		none (1), (S1 also works OK)
 IBM TP T20, model 2647-44G	none (1), video is S3 Inc. 86C270-294 Savage/IX-MV, vesafb gets "interesting" but X work.
 IBM TP A31 / Type 2652-M5G      s3_mode (3) [works ok with BIOS 1.04 2002-08-23, but not at all with BIOS 1.11 2004-11-05 :-(]
 IBM TP R32 / Type 2658-MMG      none (1)
@@ -120,18 +121,24 @@ IBM ThinkPad T42p (2373-GTG)	s3_bios (2)
 IBM TP X20			??? (*)
 IBM TP X30			s3_bios (2)
 IBM TP X31 / Type 2672-XXH      none (1), use radeontool (http://fdd.com/software/radeon/) to turn off backlight.
-IBM TP X32			none (1), but backlight is on and video is trashed after long suspend
+IBM TP X32			none (1), but backlight is on and video is trashed after long suspend. s3_bios,s3_mode (4) works too. Perhaps that gets better results?
 IBM Thinkpad X40 Type 2371-7JG  s3_bios,s3_mode (4)
+IBM TP 600e			none(1), but a switch to console and back to X is needed
 Medion MD4220			??? (*)
 Samsung P35			vbetool needed (6)
-Sharp PC-AR10 (ATI rage)	none (1)
+Sharp PC-AR10 (ATI rage)	none (1), backlight does not switch off
 Sony Vaio PCG-C1VRX/K		s3_bios (2)
 Sony Vaio PCG-F403		??? (*)
+Sony Vaio PCG-GRT995MP		none (1), works with 'nv' X driver
+Sony Vaio PCG-GR7/K		none (1), but needs radeonfb, use radeontool (http://fdd.com/software/radeon/) to turn off backlight.
 Sony Vaio PCG-N505SN		??? (*)
 Sony Vaio vgn-s260		X or boot-radeon can init it (5)
+Sony Vaio vgn-S580BH		vga=normal, but suspend from X. Console will be blank unless you return to X. 
+Sony Vaio vgn-FS115B		s3_bios (2),s3_mode (4)
 Toshiba Libretto L5		none (1)
-Toshiba Satellite 4030CDT	s3_mode (3)
-Toshiba Satellite 4080XCDT      s3_mode (3)
+Toshiba Portege 3020CT		s3_mode (3)
+Toshiba Satellite 4030CDT	s3_mode (3) (S1 also works OK)
+Toshiba Satellite 4080XCDT      s3_mode (3) (S1 also works OK)
 Toshiba Satellite 4090XCDT      ??? (*)
 Toshiba Satellite P10-554       s3_bios,s3_mode (4)(****)
 Toshiba M30                     (2) xor X with nvidia driver using internal AGP
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 28de118..02a1b3a 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -83,7 +83,7 @@ int freeze_processes(void)
 		yield();			/* Yield is okay here */
 		if (todo && time_after(jiffies, start_time + TIMEOUT)) {
 			printk( "\n" );
-			printk(KERN_ERR " stopping tasks failed (%d tasks remaining)\n", todo );
+			printk(KERN_ERR " stopping tasks timed out (%d tasks remaining)\n", todo );
 			break;
 		}
 	} while(todo);
 

-- 
Thanks, Sharp!

[PATCH] swsusp: documentation updates

[Pavel Machek]

Update documentation a bit, add more machines to video.txt list.

Signed-off-by: Pavel Machek <pavel@suse.cz>

diff --git a/Documentation/power/swsusp.txt b/Documentation/power/swsusp.txt
index d7814a1..3fcec52 100644
--- a/Documentation/power/swsusp.txt
+++ b/Documentation/power/swsusp.txt
@@ -349,9 +349,34 @@ Q: How do I make suspend more verbose?
 
 A: If you want to see any non-error kernel messages on the virtual
 terminal the kernel switches to during suspend, you have to set the
-kernel console loglevel to at least 5, for example by doing
+kernel console loglevel to at least 4 (KERN_WARNING), for example by
+doing
 
-	echo 5 > /proc/sys/kernel/printk
+	# save the old loglevel
+	read LOGLEVEL DUMMY < /proc/sys/kernel/printk
+	# set the loglevel so we see the progress bar.
+	# if the level is higher than needed, we leave it alone.
+	if [ $LOGLEVEL -lt 5 ]; then
+	        echo 5 > /proc/sys/kernel/printk
+		fi
+
+        IMG_SZ=0
+        read IMG_SZ < /sys/power/image_size
+        echo -n disk > /sys/power/state
+        RET=$?      
+        #
+        # the logic here is:
+        # if image_size > 0 (without kernel support, IMG_SZ will be zero),
+        # then try again with image_size set to zero.
+	if [ $RET -ne 0 -a $IMG_SZ -ne 0 ]; then # try again with minimal image size
+                echo 0 > /sys/power/image_size
+                echo -n disk > /sys/power/state
+                RET=$?
+        fi
+
+	# restore previous loglevel
+	echo $LOGLEVEL > /proc/sys/kernel/printk
+	exit $RET
 
 Q: Is this true that if I have a mounted filesystem on a USB device and
 I suspend to disk, I can lose data unless the filesystem has been mounted
@@ -371,3 +396,17 @@ mounted filesystem.  With USB that's tru
 The safest thing is to unmount all USB-based filesystems before suspending
 and remount them after resuming.
 
+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
+suspend to disk (and resume) is much slower on 2.6.16 compared to
+2.6.15. Any idea for why that might happen or how can I speed it up?
+
+A: This is because the size of the suspend image is now greater than
+for 2.6.15 (by saving more data we can get more responsive system
+after resume).
+
+There's the /sys/power/image_size knob that controls the size of the
+image.  If you set it to 0 (eg. by echo 0 > /sys/power/image_size as
+root), the 2.6.15 behavior should be restored.  If it is still too
+slow, take a look at suspend.sf.net -- userland suspend is faster and
+supports LZF compression to speed it up further.
diff --git a/Documentation/power/video.txt b/Documentation/power/video.txt
index 43a889f..d859faa 100644
--- a/Documentation/power/video.txt
+++ b/Documentation/power/video.txt
@@ -90,6 +90,7 @@ Table of known working notebooks:
 Model                           hack (or "how to do it")
 ------------------------------------------------------------------------------
 Acer Aspire 1406LC		ole's late BIOS init (7), turn off DRI
+Acer TM 230			s3_bios (2)
 Acer TM 242FX			vbetool (6)
 Acer TM C110			video_post (8)
 Acer TM C300                    vga=normal (only suspend on console, not in X), vbetool (6) or video_post (8)
@@ -115,6 +116,7 @@ Dell D610			vga=normal and X (possibly v
 Dell Inspiron 4000		??? (*)
 Dell Inspiron 500m		??? (*)
 Dell Inspiron 510m		???
+Dell Inspiron 5150		vbetool needed (6)
 Dell Inspiron 600m		??? (*)
 Dell Inspiron 8200		??? (*)
 Dell Inspiron 8500		??? (*)
@@ -125,6 +127,7 @@ HP NX7000			??? (*)
 HP Pavilion ZD7000		vbetool post needed, need open-source nv driver for X
 HP Omnibook XE3	athlon version	none (1)
 HP Omnibook XE3GC		none (1), video is S3 Savage/IX-MV
+HP Omnibook XE3L-GF		vbetool (6)
 HP Omnibook 5150		none (1), (S1 also works OK)
 IBM TP T20, model 2647-44G	none (1), video is S3 Inc. 86C270-294 Savage/IX-MV, vesafb gets "interesting" but X work.
 IBM TP A31 / Type 2652-M5G      s3_mode (3) [works ok with BIOS 1.04 2002-08-23, but not at all with BIOS 1.11 2004-11-05 :-(]
@@ -157,6 +160,7 @@ Sony Vaio vgn-s260		X or boot-radeon can
 Sony Vaio vgn-S580BH		vga=normal, but suspend from X. Console will be blank unless you return to X.
 Sony Vaio vgn-FS115B		s3_bios (2),s3_mode (4)
 Toshiba Libretto L5		none (1)
+Toshiba Libretto 100CT/110CT    vbetool (6)
 Toshiba Portege 3020CT		s3_mode (3)
 Toshiba Satellite 4030CDT	s3_mode (3) (S1 also works OK)
 Toshiba Satellite 4080XCDT      s3_mode (3) (S1 also works OK)


-- 
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(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

[patch] swsusp: documentation updates

[Pavel Machek]

This updates documentation and fixes pointers in MAINTAINERS file.

Signed-off-by: Pavel Machek <pavel@suse.cz>

--- clean/Documentation/power/swsusp.txt	2005-01-22 21:24:50.000000000 +0100
+++ linux/Documentation/power/swsusp.txt	2005-04-17 21:06:32.000000000 +0200
@@ -164,11 +171,11 @@
 should be held at that point and it must be safe to sleep there), and
 add:
 
-            if (current->flags & PF_FREEZE)
-                    refrigerator(PF_FREEZE);
+	try_to_freeze(PF_FREEZE);
 
 If the thread is needed for writing the image to storage, you should
-instead set the PF_NOFREEZE process flag when creating the thread.
+instead set the PF_NOFREEZE process flag when creating the thread (and
+be very carefull).
 
 
 Q: What is the difference between between "platform", "shutdown" and
@@ -233,3 +240,81 @@
 cat `cat /proc/[0-9]*/maps | grep / | sed 's:.* /:/:' | sort -u` > /dev/null
 
 after resume. swapoff -a; swapon -a may also be usefull.
+
+Q: What happens to devices during swsusp? They seem to be resumed
+during system suspend?
+
+A: That's correct. We need to resume them if we want to write image to
+disk. Whole sequence goes like
+
+      Suspend part
+      ~~~~~~~~~~~~
+      running system, user asks for suspend-to-disk
+
+      user processes are stopped
+      
+      suspend(PMSG_FREEZE): devices are frozen so that they don't interfere
+      		      with state snapshot
+		
+      state snapshot: copy of whole used memory is taken with interrupts disabled
+      
+      resume(): devices are woken up so that we can write image to swap
+      
+      write image to swap
+      
+      suspend(PMSG_SUSPEND): suspend devices so that we can power off
+      
+      turn the power off
+      
+      Resume part
+      ~~~~~~~~~~~
+      (is actually pretty similar)
+      
+      running system, user asks for suspend-to-disk
+      
+      user processes are stopped (in common case there are none, but with resume-from-initrd, noone knows)
+      
+      read image from disk
+      
+      suspend(PMSG_FREEZE): devices are frozen so that they don't interfere
+      		      with image restoration
+		
+      image restoration: rewrite memory with image
+      
+      resume(): devices are woken up so that system can continue
+      
+      thaw all user processes
+
+Q: What is this 'Encrypt suspend image' for?
+
+A: First of all: it is not a replacement for dm-crypt encrypted swap.
+It cannot protect your computer while it is suspended. Instead it does
+protect from leaking sensitive data after resume from suspend.
+
+Think of the following: you suspend while an application is running
+that keeps sensitive data in memory. The application itself prevents
+the data from being swapped out. Suspend, however, must write these
+data to swap to be able to resume later on. Without suspend encryption
+your sensitive data are then stored in plaintext on disk.  This means
+that after resume your sensitive data are accessible to all
+applications having direct access to the swap device which was used
+for suspend. If you don't need swap after resume these data can remain
+on disk virtually forever. Thus it can happen that your system gets
+broken in weeks later and sensitive data which you thought were
+encrypted and protected are retrieved and stolen from the swap device.
+To prevent this situation you should use 'Encrypt suspend image'.
+
+During suspend a temporary key is created and this key is used to
+encrypt the data written to disk. When, during resume, the data was
+read back into memory the temporary key is destroyed which simply
+means that all data written to disk during suspend are then
+inaccessible so they can't be stolen later on.  The only thing that
+you must then take care of is that you call 'mkswap' for the swap
+partition used for suspend as early as possible during regular
+boot. This asserts that any temporary key from an oopsed suspend or
+from a failed or aborted resume is erased from the swap device.
+
+As a rule of thumb use encrypted swap to protect your data while your
+system is shut down or suspended. Additionally use the encrypted
+suspend image to prevent sensitive data from being stolen after
+resume.
--- clean/MAINTAINERS	2005-04-21 12:00:27.000000000 +0200
+++ linux/MAINTAINERS	2005-04-21 12:02:36.000000000 +0200
@@ -2090,9 +2090,7 @@
 SOFTWARE SUSPEND:
 P:	Pavel Machek
 M:	pavel@suse.cz
-M:	pavel@ucw.cz
-L:	http://lister.fornax.hu/mailman/listinfo/swsusp
-W:	http://swsusp.sf.net/
+L:	linux-pm@osdl.org
 S:	Maintained
 
 SONIC NETWORK DRIVER

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