path: root/Documentation/power/basic-pm-debugging.txt
AgeCommit message (Collapse)Author
2015-02-26PM / sleep: add configurable delay for pm_testBrian Norris
When CONFIG_PM_DEBUG=y, we provide a sysfs file (/sys/power/pm_test) for selecting one of a few suspend test modes, where rather than entering a full suspend state, the kernel will perform some subset of suspend steps, wait 5 seconds, and then resume back to normal operation. This mode is useful for (among other things) observing the state of the system just before entering a sleep mode, for debugging or analysis purposes. However, a constant 5 second wait is not sufficient for some sorts of analysis; for example, on an SoC, one might want to use external tools to probe the power states of various on-chip controllers or clocks. This patch turns this 5 second delay into a configurable module parameter, so users can determine how long to wait in this pseudo-suspend state before resuming the system. Example (wait 30 seconds); # echo 30 > /sys/module/suspend/parameters/pm_test_delay # echo core > /sys/power/pm_test # time echo mem > /sys/power/state ... [ 17.583625] suspend debug: Waiting for 30 second(s). ... real 0m30.381s user 0m0.017s sys 0m0.080s Signed-off-by: Brian Norris <computersforpeace@gmail.com> Acked-by: Pavel Machek <pavel@ucw.cz> Reviewed-by: Kevin Cernekee <cernekee@chromium.org> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-01-12Documentation/: update FireWire debugging documentationLubomir Rintel
The old firewire stack is long dead now and a new version firescope has been released with support for current kernels. Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Cc: Rob Landley <rob@landley.net> Cc: Justin P. Mattock <justinmattock@gmail.com> Cc: Bernhard Kaindl <bk@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2013-08-27power: Documentation: Update s2ram linkJens Frederich
The s2ram link is broken because there is a new OpenSuse wiki online. The page does no longer exist, it was merged in the Suspend_to_RAM page. Signed-off-by: Jens Frederich <jfrederich@gmail.com> Acked-by: Rob Landley <rob@landley.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-01-19PM / Documentation: Fix spelling mistake in basic-pm-debugging.txtViresh Kumar
Signed-off-by: Viresh Kumar <viresh.kumar@st.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-10-25Merge branch 'pm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm * 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (63 commits) PM / Clocks: Remove redundant NULL checks before kfree() PM / Documentation: Update docs about suspend and CPU hotplug ACPI / PM: Add Sony VGN-FW21E to nonvs blacklist. ARM: mach-shmobile: sh7372 A4R support (v4) ARM: mach-shmobile: sh7372 A3SP support (v4) PM / Sleep: Mark devices involved in wakeup signaling during suspend PM / Hibernate: Improve performance of LZO/plain hibernation, checksum image PM / Hibernate: Do not initialize static and extern variables to 0 PM / Freezer: Make fake_signal_wake_up() wake TASK_KILLABLE tasks too PM / Hibernate: Add resumedelay kernel param in addition to resumewait MAINTAINERS: Update linux-pm list address PM / ACPI: Blacklist Vaio VGN-FW520F machine known to require acpi_sleep=nonvs PM / ACPI: Blacklist Sony Vaio known to require acpi_sleep=nonvs PM / Hibernate: Add resumewait param to support MMC-like devices as resume file PM / Hibernate: Fix typo in a kerneldoc comment PM / Hibernate: Freeze kernel threads after preallocating memory PM: Update the policy on default wakeup settings PM / VT: Cleanup #if defined uglyness and fix compile error PM / Suspend: Off by one in pm_suspend() PM / Hibernate: Include storage keys in hibernation image on s390 ...
2011-10-16PM / Suspend: Add statistics debugfs file for suspend to RAMShuoX Liu
Record S3 failure time about each reason and the latest two failed devices' names in S3 progress. We can check it through 'suspend_stats' entry in debugfs. The motivation of the patch: We are enabling power features on Medfield. Comparing with PC/notebook, a mobile enters/exits suspend-2-ram (we call it s3 on Medfield) far more frequently. If it can't enter suspend-2-ram in time, the power might be used up soon. We often find sometimes, a device suspend fails. Then, system retries s3 over and over again. As display is off, testers and developers don't know what happens. Some testers and developers complain they don't know if system tries suspend-2-ram, and what device fails to suspend. They need such info for a quick check. The patch adds suspend_stats under debugfs for users to check suspend to RAM statistics quickly. If not using this patch, we have other methods to get info about what device fails. One is to turn on CONFIG_PM_DEBUG, but users would get too much info and testers need recompile the system. In addition, dynamic debug is another good tool to dump debug info. But it still doesn't match our utilization scenario closely. 1) user need write a user space parser to process the syslog output; 2) Our testing scenario is we leave the mobile for at least hours. Then, check its status. No serial console available during the testing. One is because console would be suspended, and the other is serial console connecting with spi or HSU devices would consume power. These devices are powered off at suspend-2-ram. Signed-off-by: ShuoX Liu <shuox.liu@intel.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-09-27doc: fix broken referencesPaul Bolle
There are numerous broken references to Documentation files (in other Documentation files, in comments, etc.). These broken references are caused by typo's in the references, and by renames or removals of the Documentation files. Some broken references are simply odd. Fix these broken references, sometimes by dropping the irrelevant text they were part of. Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-08-04Documentation: update broken web addresses.Justin P. Mattock
Below you will find an updated version from the original series bunching all patches into one big patch updating broken web addresses that are located in Documentation/* Some of the addresses date as far far back as 1995 etc... so searching became a bit difficult, the best way to deal with these is to use web.archive.org to locate these addresses that are outdated. Now there are also some addresses pointing to .spec files some are located, but some(after searching on the companies site)where still no where to be found. In this case I just changed the address to the company site this way the users can contact the company and they can locate them for the users. Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Signed-off-by: Thomas Weber <weber@corscience.de> Signed-off-by: Mike Frysinger <vapier.adi@gmail.com> Cc: Paulo Marques <pmarques@grupopie.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Michael Neuling <mikey@neuling.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2008-02-01PM: Suspend/hibernation debug documentation update (rev. 2)Rafael J. Wysocki
Update the suspend/hibernation debugging and testing documentation to describe the newly introduced testing facilities. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Len Brown <len.brown@intel.com>
2007-10-18serial: turn serial console suspend a boot rather than compile time optionAndres Salomon
Currently, there's a CONFIG_DISABLE_CONSOLE_SUSPEND that allows one to stop the serial console from being suspended when the rest of the machine goes to sleep. This is incredibly useful for debugging power management-related things; however, having it as a compile-time option has proved to be incredibly inconvenient for us (OLPC). There are plenty of times that we want serial console to not suspend, but for the most part we'd like serial console to be suspended. This drops CONFIG_DISABLE_CONSOLE_SUSPEND, and replaces it with a kernel boot parameter (no_console_suspend). By default, the serial console will be suspended along with the rest of the system; by passing 'no_console_suspend' to the kernel during boot, serial console will remain alive during suspend. For now, this is pretty serial console specific; further fixes could be applied to make this work for things like netconsole. Signed-off-by: Andres Salomon <dilinger@debian.org> Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Nigel Cunningham <nigel@suspend2.net> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08Documentation: Ask driver writers to provide PM supportRafael J. Wysocki
Add a paragraph in Documentation/SubmittingDrivers requesting that the basic PM support be provided by new device drivers. Add two new documents in Documentation/power/ giving general instructions on debugging the suspend/resume functionality and testing the suspend and resume support in device drivers. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Pavel Machek <pavel@ucw.cz> Cc: David Brownell <david-b@pacbell.net> Cc: Nigel Cunningham <ncunningham@linuxmail.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>