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authorPavel Machek <pavel@ucw.cz>2006-03-23 06:00:02 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-23 10:38:07 -0500
commit543cc27d09643640cbc34189c03a40beb8227aef (patch)
tree034b4141ed5ac76b220d55c738a0eda668c1a490 /Documentation/power
parent74c7e2efbe37378026f00ad9e7253796d7b2fc99 (diff)
[PATCH] swsusp: documentation updates
Update 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). From: "Rafael J. Wysocki" <rjw@sisk.pl> Warn in the documentation that data may be lost if there are some filesystems mounted from USB devices before suspend. [Thanks to Alan Stern for providing the answer to the question in the Q:-A: part.] Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'Documentation/power')
-rw-r--r--Documentation/power/swsusp.txt51
-rw-r--r--Documentation/power/video.txt74
2 files changed, 77 insertions, 48 deletions
diff --git a/Documentation/power/swsusp.txt b/Documentation/power/swsusp.txt
index b28b7f04abb8..d7814a113ee1 100644
--- a/Documentation/power/swsusp.txt
+++ b/Documentation/power/swsusp.txt
@@ -17,6 +17,11 @@ Some warnings, first.
17 * but it will probably only crash. 17 * but it will probably only crash.
18 * 18 *
19 * (*) suspend/resume support is needed to make it safe. 19 * (*) suspend/resume support is needed to make it safe.
20 *
21 * If you have any filesystems on USB devices mounted before suspend,
22 * they won't be accessible after resume and you may lose data, as though
23 * you have unplugged the USB devices with mounted filesystems on them
24 * (see the FAQ below for details).
20 25
21You need to append resume=/dev/your_swap_partition to kernel command 26You need to append resume=/dev/your_swap_partition to kernel command
22line. Then you suspend by 27line. Then you suspend by
@@ -27,19 +32,18 @@ echo shutdown > /sys/power/disk; echo disk > /sys/power/state
27 32
28echo platform > /sys/power/disk; echo disk > /sys/power/state 33echo platform > /sys/power/disk; echo disk > /sys/power/state
29 34
35. If you have SATA disks, you'll need recent kernels with SATA suspend
36support. For suspend and resume to work, make sure your disk drivers
37are built into kernel -- not modules. [There's way to make
38suspend/resume with modular disk drivers, see FAQ, but you probably
39should not do that.]
40
30If you want to limit the suspend image size to N bytes, do 41If you want to limit the suspend image size to N bytes, do
31 42
32echo N > /sys/power/image_size 43echo N > /sys/power/image_size
33 44
34before suspend (it is limited to 500 MB by default). 45before suspend (it is limited to 500 MB by default).
35 46
36Encrypted suspend image:
37------------------------
38If you want to store your suspend image encrypted with a temporary
39key to prevent data gathering after resume you must compile
40crypto and the aes algorithm into the kernel - modules won't work
41as they cannot be loaded at resume time.
42
43 47
44Article about goals and implementation of Software Suspend for Linux 48Article about goals and implementation of Software Suspend for Linux
45~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 49~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -333,4 +337,37 @@ init=/bin/bash, then swapon and starting suspend sequence manually
333usually does the trick. Then it is good idea to try with latest 337usually does the trick. Then it is good idea to try with latest
334vanilla kernel. 338vanilla kernel.
335 339
340Q: How can distributions ship a swsusp-supporting kernel with modular
341disk drivers (especially SATA)?
342
343A: Well, it can be done, load the drivers, then do echo into
344/sys/power/disk/resume file from initrd. Be sure not to mount
345anything, not even read-only mount, or you are going to lose your
346data.
347
348Q: How do I make suspend more verbose?
349
350A: If you want to see any non-error kernel messages on the virtual
351terminal the kernel switches to during suspend, you have to set the
352kernel console loglevel to at least 5, for example by doing
353
354 echo 5 > /proc/sys/kernel/printk
355
356Q: Is this true that if I have a mounted filesystem on a USB device and
357I suspend to disk, I can lose data unless the filesystem has been mounted
358with "sync"?
359
360A: That's right. It depends on your hardware, and it could be true even for
361suspend-to-RAM. In fact, even with "-o sync" you can lose data if your
362programs have information in buffers they haven't written out to disk.
363
364If you're lucky, your hardware will support low-power modes for USB
365controllers while the system is asleep. Lots of hardware doesn't,
366however. Shutting off the power to a USB controller is equivalent to
367unplugging all the attached devices.
368
369Remember that it's always a bad idea to unplug a disk drive containing a
370mounted filesystem. With USB that's true even when your system is asleep!
371The safest thing is to unmount all USB-based filesystems before suspending
372and remount them after resuming.
336 373
diff --git a/Documentation/power/video.txt b/Documentation/power/video.txt
index 912bed87c758..d18a57d1a531 100644
--- a/Documentation/power/video.txt
+++ b/Documentation/power/video.txt
@@ -1,7 +1,7 @@
1 1
2 Video issues with S3 resume 2 Video issues with S3 resume
3 ~~~~~~~~~~~~~~~~~~~~~~~~~~~ 3 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
4 2003-2005, Pavel Machek 4 2003-2006, Pavel Machek
5 5
6During S3 resume, hardware needs to be reinitialized. For most 6During S3 resume, hardware needs to be reinitialized. For most
7devices, this is easy, and kernel driver knows how to do 7devices, this is easy, and kernel driver knows how to do
@@ -15,6 +15,27 @@ run normally so video card is normally initialized. It should not be
15problem for S1 standby, because hardware should retain its state over 15problem for S1 standby, because hardware should retain its state over
16that. 16that.
17 17
18We either have to run video BIOS during early resume, or interpret it
19using vbetool later, or maybe nothing is neccessary on particular
20system because video state is preserved. Unfortunately different
21methods work on different systems, and no known method suits all of
22them.
23
24Userland application called s2ram has been developed; it contains long
25whitelist of systems, and automatically selects working method for a
26given system. It can be downloaded from CVS at
27www.sf.net/projects/suspend . If you get a system that is not in the
28whitelist, please try to find a working solution, and submit whitelist
29entry so that work does not need to be repeated.
30
31Currently, VBE_SAVE method (6 below) works on most
32systems. Unfortunately, vbetool only runs after userland is resumed,
33so it makes debugging of early resume problems
34hard/impossible. Methods that do not rely on userland are preferable.
35
36Details
37~~~~~~~
38
18There are a few types of systems where video works after S3 resume: 39There are a few types of systems where video works after S3 resume:
19 40
20(1) systems where video state is preserved over S3. 41(1) systems where video state is preserved over S3.
@@ -104,6 +125,7 @@ HP NX7000 ??? (*)
104HP Pavilion ZD7000 vbetool post needed, need open-source nv driver for X 125HP Pavilion ZD7000 vbetool post needed, need open-source nv driver for X
105HP Omnibook XE3 athlon version none (1) 126HP Omnibook XE3 athlon version none (1)
106HP Omnibook XE3GC none (1), video is S3 Savage/IX-MV 127HP Omnibook XE3GC none (1), video is S3 Savage/IX-MV
128HP Omnibook 5150 none (1), (S1 also works OK)
107IBM TP T20, model 2647-44G none (1), video is S3 Inc. 86C270-294 Savage/IX-MV, vesafb gets "interesting" but X work. 129IBM TP T20, model 2647-44G none (1), video is S3 Inc. 86C270-294 Savage/IX-MV, vesafb gets "interesting" but X work.
108IBM 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 :-(] 130IBM 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 :-(]
109IBM TP R32 / Type 2658-MMG none (1) 131IBM TP R32 / Type 2658-MMG none (1)
@@ -120,18 +142,24 @@ IBM ThinkPad T42p (2373-GTG) s3_bios (2)
120IBM TP X20 ??? (*) 142IBM TP X20 ??? (*)
121IBM TP X30 s3_bios (2) 143IBM TP X30 s3_bios (2)
122IBM TP X31 / Type 2672-XXH none (1), use radeontool (http://fdd.com/software/radeon/) to turn off backlight. 144IBM TP X31 / Type 2672-XXH none (1), use radeontool (http://fdd.com/software/radeon/) to turn off backlight.
123IBM TP X32 none (1), but backlight is on and video is trashed after long suspend 145IBM 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?
124IBM Thinkpad X40 Type 2371-7JG s3_bios,s3_mode (4) 146IBM Thinkpad X40 Type 2371-7JG s3_bios,s3_mode (4)
147IBM TP 600e none(1), but a switch to console and back to X is needed
125Medion MD4220 ??? (*) 148Medion MD4220 ??? (*)
126Samsung P35 vbetool needed (6) 149Samsung P35 vbetool needed (6)
127Sharp PC-AR10 (ATI rage) none (1) 150Sharp PC-AR10 (ATI rage) none (1), backlight does not switch off
128Sony Vaio PCG-C1VRX/K s3_bios (2) 151Sony Vaio PCG-C1VRX/K s3_bios (2)
129Sony Vaio PCG-F403 ??? (*) 152Sony Vaio PCG-F403 ??? (*)
153Sony Vaio PCG-GRT995MP none (1), works with 'nv' X driver
154Sony Vaio PCG-GR7/K none (1), but needs radeonfb, use radeontool (http://fdd.com/software/radeon/) to turn off backlight.
130Sony Vaio PCG-N505SN ??? (*) 155Sony Vaio PCG-N505SN ??? (*)
131Sony Vaio vgn-s260 X or boot-radeon can init it (5) 156Sony Vaio vgn-s260 X or boot-radeon can init it (5)
157Sony Vaio vgn-S580BH vga=normal, but suspend from X. Console will be blank unless you return to X.
158Sony Vaio vgn-FS115B s3_bios (2),s3_mode (4)
132Toshiba Libretto L5 none (1) 159Toshiba Libretto L5 none (1)
133Toshiba Satellite 4030CDT s3_mode (3) 160Toshiba Portege 3020CT s3_mode (3)
134Toshiba Satellite 4080XCDT s3_mode (3) 161Toshiba Satellite 4030CDT s3_mode (3) (S1 also works OK)
162Toshiba Satellite 4080XCDT s3_mode (3) (S1 also works OK)
135Toshiba Satellite 4090XCDT ??? (*) 163Toshiba Satellite 4090XCDT ??? (*)
136Toshiba Satellite P10-554 s3_bios,s3_mode (4)(****) 164Toshiba Satellite P10-554 s3_bios,s3_mode (4)(****)
137Toshiba M30 (2) xor X with nvidia driver using internal AGP 165Toshiba M30 (2) xor X with nvidia driver using internal AGP
@@ -151,39 +179,3 @@ Asus A7V8X nVidia RIVA TNT2 model 64 s3_bios,s3_mode (4)
151(***) To be tested with a newer kernel. 179(***) To be tested with a newer kernel.
152 180
153(****) Not with SMP kernel, UP only. 181(****) Not with SMP kernel, UP only.
154
155VBEtool details
156~~~~~~~~~~~~~~~
157(with thanks to Carl-Daniel Hailfinger)
158
159First, boot into X and run the following script ONCE:
160#!/bin/bash
161statedir=/root/s3/state
162mkdir -p $statedir
163chvt 2
164sleep 1
165vbetool vbestate save >$statedir/vbe
166
167
168To suspend and resume properly, call the following script as root:
169#!/bin/bash
170statedir=/root/s3/state
171curcons=`fgconsole`
172fuser /dev/tty$curcons 2>/dev/null|xargs ps -o comm= -p|grep -q X && chvt 2
173cat /dev/vcsa >$statedir/vcsa
174sync
175echo 3 >/proc/acpi/sleep
176sync
177vbetool post
178vbetool vbestate restore <$statedir/vbe
179cat $statedir/vcsa >/dev/vcsa
180rckbd restart
181chvt $[curcons%6+1]
182chvt $curcons
183
184
185Unless you change your graphics card or other hardware configuration,
186the state once saved will be OK for every resume afterwards.
187NOTE: The "rckbd restart" command may be different for your
188distribution. Simply replace it with the command you would use to
189set the fonts on screen.