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-rw-r--r--Documentation/power/pci.txt38
-rw-r--r--Documentation/power/swsusp.txt83
-rw-r--r--Documentation/power/video.txt3
-rw-r--r--Documentation/power/video_extension.txt19
4 files changed, 133 insertions, 10 deletions
diff --git a/Documentation/power/pci.txt b/Documentation/power/pci.txt
index 35b1a7dae342..6fc9d511fc39 100644
--- a/Documentation/power/pci.txt
+++ b/Documentation/power/pci.txt
@@ -291,6 +291,44 @@ a request to enable wake events from D3, two calls should be made to
pci_enable_wake (one for both D3hot and D3cold).
+A reference implementation
+-------------------------
+.suspend()
+{
+ /* driver specific operations */
+
+ /* Disable IRQ */
+ free_irq();
+ /* If using MSI */
+ pci_disable_msi();
+
+ pci_save_state();
+ pci_enable_wake();
+ /* Disable IO/bus master/irq router */
+ pci_disable_device();
+ pci_set_power_state(pci_choose_state());
+}
+
+.resume()
+{
+ pci_set_power_state(PCI_D0);
+ pci_restore_state();
+ /* device's irq possibly is changed, driver should take care */
+ pci_enable_device();
+ pci_set_master();
+
+ /* if using MSI, device's vector possibly is changed */
+ pci_enable_msi();
+
+ request_irq();
+ /* driver specific operations; */
+}
+
+This is a typical implementation. Drivers can slightly change the order
+of the operations in the implementation, ignore some operations or add
+more deriver specific operations in it, but drivers should do something like
+this on the whole.
+
5. Resources
~~~~~~~~~~~~
diff --git a/Documentation/power/swsusp.txt b/Documentation/power/swsusp.txt
index 4e1627cc5b51..7a6b78966459 100644
--- a/Documentation/power/swsusp.txt
+++ b/Documentation/power/swsusp.txt
@@ -164,10 +164,11 @@ place where the thread is safe to be frozen (no kernel semaphores
should be held at that point and it must be safe to sleep there), and
add:
- try_to_freeze();
+ try_to_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
@@ -232,3 +233,81 @@ A: Try running
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.
diff --git a/Documentation/power/video.txt b/Documentation/power/video.txt
index 68734355d7cf..881a37e3eeb0 100644
--- a/Documentation/power/video.txt
+++ b/Documentation/power/video.txt
@@ -83,8 +83,10 @@ Compaq Armada E500 - P3-700 none (1) (S1 also works OK)
Compaq Evo N620c vga=normal, s3_bios (2)
Dell 600m, ATI R250 Lf none (1), but needs xorg-x11-6.8.1.902-1
Dell D600, ATI RV250 vga=normal and X, or try vbestate (6)
+Dell D610 vga=normal and X (possibly vbestate (6) too, but not tested)
Dell Inspiron 4000 ??? (*)
Dell Inspiron 500m ??? (*)
+Dell Inspiron 510m ???
Dell Inspiron 600m ??? (*)
Dell Inspiron 8200 ??? (*)
Dell Inspiron 8500 ??? (*)
@@ -123,6 +125,7 @@ Toshiba Satellite 4030CDT s3_mode (3)
Toshiba Satellite 4080XCDT s3_mode (3)
Toshiba Satellite 4090XCDT ??? (*)
Toshiba Satellite P10-554 s3_bios,s3_mode (4)(****)
+Toshiba M30 (2) xor X with nvidia driver using internal AGP
Uniwill 244IIO ??? (*)
diff --git a/Documentation/power/video_extension.txt b/Documentation/power/video_extension.txt
index 8e33d7c82c49..b2f9b1598ac2 100644
--- a/Documentation/power/video_extension.txt
+++ b/Documentation/power/video_extension.txt
@@ -1,13 +1,16 @@
-This driver implement the ACPI Extensions For Display Adapters
-for integrated graphics devices on motherboard, as specified in
-ACPI 2.0 Specification, Appendix B, allowing to perform some basic
-control like defining the video POST device, retrieving EDID information
-or to setup a video output, etc. Note that this is an ref. implementation only.
-It may or may not work for your integrated video device.
+ACPI video extensions
+~~~~~~~~~~~~~~~~~~~~~
+
+This driver implement the ACPI Extensions For Display Adapters for
+integrated graphics devices on motherboard, as specified in ACPI 2.0
+Specification, Appendix B, allowing to perform some basic control like
+defining the video POST device, retrieving EDID information or to
+setup a video output, etc. Note that this is an ref. implementation
+only. It may or may not work for your integrated video device.
Interfaces exposed to userland through /proc/acpi/video:
-VGA/info : display the supported video bus device capability like ,Video ROM, CRT/LCD/TV.
+VGA/info : display the supported video bus device capability like Video ROM, CRT/LCD/TV.
VGA/ROM : Used to get a copy of the display devices' ROM data (up to 4k).
VGA/POST_info : Used to determine what options are implemented.
VGA/POST : Used to get/set POST device.
@@ -15,7 +18,7 @@ VGA/DOS : Used to get/set ownership of output switching:
Please refer ACPI spec B.4.1 _DOS
VGA/CRT : CRT output
VGA/LCD : LCD output
-VGA/TV : TV output
+VGA/TVO : TV output
VGA/*/brightness : Used to get/set brightness of output device
Notify event through /proc/acpi/event: