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authorAnton Altaparmakov <aia21@cantab.net>2006-03-23 17:06:08 +0000
committerAnton Altaparmakov <aia21@cantab.net>2006-03-23 17:06:08 +0000
commit92fe7b9ea8ef101bff3c75ade89b93b5f62a7955 (patch)
tree3dba4faa78f1bbe4be503275173e3a63b5d60f22 /Documentation
parente750d1c7cc314b9ba1934b0b474b7d39f906f865 (diff)
parentb0e6e962992b76580f4900b166a337bad7c1e81b (diff)
downloadlwn-92fe7b9ea8ef101bff3c75ade89b93b5f62a7955.tar.gz
lwn-92fe7b9ea8ef101bff3c75ade89b93b5f62a7955.zip
Merge branch 'master' of /usr/src/ntfs-2.6/
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/kernel-parameters.txt11
-rw-r--r--Documentation/power/swsusp.txt51
-rw-r--r--Documentation/power/userland-swsusp.txt149
-rw-r--r--Documentation/power/video.txt74
4 files changed, 236 insertions, 49 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index fc99075e0af4..7b7382d0f758 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1008,7 +1008,9 @@ running once the system is up.
noexec=on: enable non-executable mappings (default)
noexec=off: disable nn-executable mappings
- nofxsr [BUGS=IA-32]
+ nofxsr [BUGS=IA-32] Disables x86 floating point extended
+ register save and restore. The kernel will only save
+ legacy floating-point registers on task switch.
nohlt [BUGS=ARM]
@@ -1053,6 +1055,8 @@ running once the system is up.
nosbagart [IA-64]
+ nosep [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
+
nosmp [SMP] Tells an SMP kernel to act as a UP kernel.
nosync [HW,M68K] Disables sync negotiation for all devices.
@@ -1122,6 +1126,11 @@ running once the system is up.
pas16= [HW,SCSI]
See header of drivers/scsi/pas16.c.
+ pause_on_oops=
+ Halt all CPUs after the first oops has been printed for
+ the specified number of seconds. This is to be used if
+ your oopses keep scrolling off the screen.
+
pcbit= [HW,ISDN]
pcd. [PARIDE]
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.
* but it will probably only crash.
*
* (*) suspend/resume support is needed to make it safe.
+ *
+ * If you have any filesystems on USB devices mounted before suspend,
+ * they won't be accessible after resume and you may lose data, as though
+ * you have unplugged the USB devices with mounted filesystems on them
+ * (see the FAQ below for details).
You need to append resume=/dev/your_swap_partition to kernel command
line. Then you suspend by
@@ -27,19 +32,18 @@ echo shutdown > /sys/power/disk; echo disk > /sys/power/state
echo platform > /sys/power/disk; echo disk > /sys/power/state
+. If you have SATA disks, you'll need recent kernels with SATA suspend
+support. For suspend and resume to work, make sure your disk drivers
+are built into kernel -- not modules. [There's way to make
+suspend/resume with modular disk drivers, see FAQ, but you probably
+should not do that.]
+
If you want to limit the suspend image size to N bytes, do
echo N > /sys/power/image_size
before suspend (it is limited to 500 MB by default).
-Encrypted suspend image:
-------------------------
-If you want to store your suspend image encrypted with a temporary
-key to prevent data gathering after resume you must compile
-crypto and the aes algorithm into the kernel - modules won't work
-as they cannot be loaded at resume time.
-
Article about goals and implementation of Software Suspend for Linux
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -333,4 +337,37 @@ init=/bin/bash, then swapon and starting suspend sequence manually
usually does the trick. Then it is good idea to try with latest
vanilla kernel.
+Q: How can distributions ship a swsusp-supporting kernel with modular
+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
+anything, not even read-only mount, or you are going to lose your
+data.
+
+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
+
+ echo 5 > /proc/sys/kernel/printk
+
+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
+with "sync"?
+
+A: That's right. It depends on your hardware, and it could be true even for
+suspend-to-RAM. In fact, even with "-o sync" you can lose data if your
+programs have information in buffers they haven't written out to disk.
+
+If you're lucky, your hardware will support low-power modes for USB
+controllers while the system is asleep. Lots of hardware doesn't,
+however. Shutting off the power to a USB controller is equivalent to
+unplugging all the attached devices.
+
+Remember that it's always a bad idea to unplug a disk drive containing a
+mounted filesystem. With USB that's true even when your system is asleep!
+The safest thing is to unmount all USB-based filesystems before suspending
+and remount them after resuming.
diff --git a/Documentation/power/userland-swsusp.txt b/Documentation/power/userland-swsusp.txt
new file mode 100644
index 000000000000..94058220aaf0
--- /dev/null
+++ b/Documentation/power/userland-swsusp.txt
@@ -0,0 +1,149 @@
+Documentation for userland software suspend interface
+ (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
+
+First, the warnings at the beginning of swsusp.txt still apply.
+
+Second, you should read the FAQ in swsusp.txt _now_ if you have not
+done it already.
+
+Now, to use the userland interface for software suspend you need special
+utilities that will read/write the system memory snapshot from/to the
+kernel. Such utilities are available, for example, from
+<http://www.sisk.pl/kernel/utilities/suspend>. You may want to have
+a look at them if you are going to develop your own suspend/resume
+utilities.
+
+The interface consists of a character device providing the open(),
+release(), read(), and write() operations as well as several ioctl()
+commands defined in kernel/power/power.h. The major and minor
+numbers of the device are, respectively, 10 and 231, and they can
+be read from /sys/class/misc/snapshot/dev.
+
+The device can be open either for reading or for writing. If open for
+reading, it is considered to be in the suspend mode. Otherwise it is
+assumed to be in the resume mode. The device cannot be open for reading
+and writing. It is also impossible to have the device open more than once
+at a time.
+
+The ioctl() commands recognized by the device are:
+
+SNAPSHOT_FREEZE - freeze user space processes (the current process is
+ not frozen); this is required for SNAPSHOT_ATOMIC_SNAPSHOT
+ and SNAPSHOT_ATOMIC_RESTORE to succeed
+
+SNAPSHOT_UNFREEZE - thaw user space processes frozen by SNAPSHOT_FREEZE
+
+SNAPSHOT_ATOMIC_SNAPSHOT - create a snapshot of the system memory; the
+ last argument of ioctl() should be a pointer to an int variable,
+ the value of which will indicate whether the call returned after
+ creating the snapshot (1) or after restoring the system memory state
+ from it (0) (after resume the system finds itself finishing the
+ SNAPSHOT_ATOMIC_SNAPSHOT ioctl() again); after the snapshot
+ has been created the read() operation can be used to transfer
+ it out of the kernel
+
+SNAPSHOT_ATOMIC_RESTORE - restore the system memory state from the
+ uploaded snapshot image; before calling it you should transfer
+ the system memory snapshot back to the kernel using the write()
+ operation; this call will not succeed if the snapshot
+ image is not available to the kernel
+
+SNAPSHOT_FREE - free memory allocated for the snapshot image
+
+SNAPSHOT_SET_IMAGE_SIZE - set the preferred maximum size of the image
+ (the kernel will do its best to ensure the image size will not exceed
+ this number, but if it turns out to be impossible, the kernel will
+ create the smallest image possible)
+
+SNAPSHOT_AVAIL_SWAP - return the amount of available swap in bytes (the last
+ argument should be a pointer to an unsigned int variable that will
+ contain the result if the call is successful).
+
+SNAPSHOT_GET_SWAP_PAGE - allocate a swap page from the resume partition
+ (the last argument should be a pointer to a loff_t variable that
+ will contain the swap page offset if the call is successful)
+
+SNAPSHOT_FREE_SWAP_PAGES - free all swap pages allocated with
+ SNAPSHOT_GET_SWAP_PAGE
+
+SNAPSHOT_SET_SWAP_FILE - set the resume partition (the last ioctl() argument
+ should specify the device's major and minor numbers in the old
+ two-byte format, as returned by the stat() function in the .st_rdev
+ member of the stat structure); it is recommended to always use this
+ call, because the code to set the resume partition could be removed from
+ future kernels
+
+The device's read() operation can be used to transfer the snapshot image from
+the kernel. It has the following limitations:
+- you cannot read() more than one virtual memory page at a time
+- read()s accross page boundaries are impossible (ie. if ypu read() 1/2 of
+ a page in the previous call, you will only be able to read()
+ _at_ _most_ 1/2 of the page in the next call)
+
+The device's write() operation is used for uploading the system memory snapshot
+into the kernel. It has the same limitations as the read() operation.
+
+The release() operation frees all memory allocated for the snapshot image
+and all swap pages allocated with SNAPSHOT_GET_SWAP_PAGE (if any).
+Thus it is not necessary to use either SNAPSHOT_FREE or
+SNAPSHOT_FREE_SWAP_PAGES before closing the device (in fact it will also
+unfreeze user space processes frozen by SNAPSHOT_UNFREEZE if they are
+still frozen when the device is being closed).
+
+Currently it is assumed that the userland utilities reading/writing the
+snapshot image from/to the kernel will use a swap parition, called the resume
+partition, as storage space. However, this is not really required, as they
+can use, for example, a special (blank) suspend partition or a file on a partition
+that is unmounted before SNAPSHOT_ATOMIC_SNAPSHOT and mounted afterwards.
+
+These utilities SHOULD NOT make any assumptions regarding the ordering of
+data within the snapshot image, except for the image header that MAY be
+assumed to start with an swsusp_info structure, as specified in
+kernel/power/power.h. This structure MAY be used by the userland utilities
+to obtain some information about the snapshot image, such as the size
+of the snapshot image, including the metadata and the header itself,
+contained in the .size member of swsusp_info.
+
+The snapshot image MUST be written to the kernel unaltered (ie. all of the image
+data, metadata and header MUST be written in _exactly_ the same amount, form
+and order in which they have been read). Otherwise, the behavior of the
+resumed system may be totally unpredictable.
+
+While executing SNAPSHOT_ATOMIC_RESTORE the kernel checks if the
+structure of the snapshot image is consistent with the information stored
+in the image header. If any inconsistencies are detected,
+SNAPSHOT_ATOMIC_RESTORE will not succeed. Still, this is not a fool-proof
+mechanism and the userland utilities using the interface SHOULD use additional
+means, such as checksums, to ensure the integrity of the snapshot image.
+
+The suspending and resuming utilities MUST lock themselves in memory,
+preferrably using mlockall(), before calling SNAPSHOT_FREEZE.
+
+The suspending utility MUST check the value stored by SNAPSHOT_ATOMIC_SNAPSHOT
+in the memory location pointed to by the last argument of ioctl() and proceed
+in accordance with it:
+1. If the value is 1 (ie. the system memory snapshot has just been
+ created and the system is ready for saving it):
+ (a) The suspending utility MUST NOT close the snapshot device
+ _unless_ the whole suspend procedure is to be cancelled, in
+ which case, if the snapshot image has already been saved, the
+ suspending utility SHOULD destroy it, preferrably by zapping
+ its header. If the suspend is not to be cancelled, the
+ system MUST be powered off or rebooted after the snapshot
+ image has been saved.
+ (b) The suspending utility SHOULD NOT attempt to perform any
+ file system operations (including reads) on the file systems
+ that were mounted before SNAPSHOT_ATOMIC_SNAPSHOT has been
+ called. However, it MAY mount a file system that was not
+ mounted at that time and perform some operations on it (eg.
+ use it for saving the image).
+2. If the value is 0 (ie. the system state has just been restored from
+ the snapshot image), the suspending utility MUST close the snapshot
+ device. Afterwards it will be treated as a regular userland process,
+ so it need not exit.
+
+The resuming utility SHOULD NOT attempt to mount any file systems that could
+be mounted before suspend and SHOULD NOT attempt to perform any operations
+involving such file systems.
+
+For details, please refer to the source code.
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 @@
Video issues with S3 resume
~~~~~~~~~~~~~~~~~~~~~~~~~~~
- 2003-2005, Pavel Machek
+ 2003-2006, Pavel Machek
During S3 resume, hardware needs to be reinitialized. For most
devices, 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
problem for S1 standby, because hardware should retain its state over
that.
+We either have to run video BIOS during early resume, or interpret it
+using vbetool later, or maybe nothing is neccessary on particular
+system because video state is preserved. Unfortunately different
+methods work on different systems, and no known method suits all of
+them.
+
+Userland application called s2ram has been developed; it contains long
+whitelist of systems, and automatically selects working method for a
+given system. It can be downloaded from CVS at
+www.sf.net/projects/suspend . If you get a system that is not in the
+whitelist, please try to find a working solution, and submit whitelist
+entry so that work does not need to be repeated.
+
+Currently, VBE_SAVE method (6 below) works on most
+systems. Unfortunately, vbetool only runs after userland is resumed,
+so it makes debugging of early resume problems
+hard/impossible. Methods that do not rely on userland are preferable.
+
+Details
+~~~~~~~
+
There are a few types of systems where video works after S3 resume:
(1) systems where video state is preserved over S3.
@@ -104,6 +125,7 @@ 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 +142,24 @@ 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
@@ -151,39 +179,3 @@ Asus A7V8X nVidia RIVA TNT2 model 64 s3_bios,s3_mode (4)
(***) To be tested with a newer kernel.
(****) Not with SMP kernel, UP only.
-
-VBEtool details
-~~~~~~~~~~~~~~~
-(with thanks to Carl-Daniel Hailfinger)
-
-First, boot into X and run the following script ONCE:
-#!/bin/bash
-statedir=/root/s3/state
-mkdir -p $statedir
-chvt 2
-sleep 1
-vbetool vbestate save >$statedir/vbe
-
-
-To suspend and resume properly, call the following script as root:
-#!/bin/bash
-statedir=/root/s3/state
-curcons=`fgconsole`
-fuser /dev/tty$curcons 2>/dev/null|xargs ps -o comm= -p|grep -q X && chvt 2
-cat /dev/vcsa >$statedir/vcsa
-sync
-echo 3 >/proc/acpi/sleep
-sync
-vbetool post
-vbetool vbestate restore <$statedir/vbe
-cat $statedir/vcsa >/dev/vcsa
-rckbd restart
-chvt $[curcons%6+1]
-chvt $curcons
-
-
-Unless you change your graphics card or other hardware configuration,
-the state once saved will be OK for every resume afterwards.
-NOTE: The "rckbd restart" command may be different for your
-distribution. Simply replace it with the command you would use to
-set the fonts on screen.