linux/kernel/power, branch v3.6-rc6

Revert "NMI watchdog: fix for lockup detector breakage on resume"

2012-08-08T18:49:45Z

Revert commit 45226e9 (NMI watchdog: fix for lockup detector breakage on resume) which breaks resume from system suspend on my SH7372 Mackerel board (by causing a NULL pointer dereference to happen) and is generally wrong, because it abuses the CPU hotplug functionality in a shamelessly blatant way. The original issue should be addressed through appropriate syscore resume callback instead. Signed-off-by: Rafael J. Wysocki

NMI watchdog: fix for lockup detector breakage on resume

2012-07-31T00:25:13Z

On the suspend/resume path the boot CPU does not go though an offline->online transition. This breaks the NMI detector post-resume since it depends on PMU state that is lost when the system gets suspended. Fix this by forcing a CPU offline->online transition for the lockup detector on the boot CPU during resume. To provide more context, we enable NMI watchdog on Chrome OS. We have seen several reports of systems freezing up completely which indicated that the NMI watchdog was not firing for some reason. Debugging further, we found a simple way of repro'ing system freezes -- issuing the command 'tasket 1 sh -c "echo nmilockup > /proc/breakme"' after the system has been suspended/resumed one or more times. With this patch in place, the system freeze result in panics, as expected. These panics provide a nice stack trace for us to debug the actual issue causing the freeze. [akpm@linux-foundation.org: fiddle with code comment] [akpm@linux-foundation.org: make lockup_detector_bootcpu_resume() conditional on CONFIG_SUSPEND] [akpm@linux-foundation.org: fix section errors] Signed-off-by: Sameer Nanda Cc: Ingo Molnar Cc: Peter Zijlstra Cc: "Rafael J. Wysocki" Cc: Don Zickus Cc: Mandeep Singh Baines Cc: Srivatsa S. Bhat Cc: Anshuman Khandual Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'pm-for-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2012-07-22T20:36:52Z

Pull power management updates from Rafael Wysocki: - ACPI conversion to PM handling based on struct dev_pm_ops. - Conversion of a number of platform drivers to PM handling based on struct dev_pm_ops and removal of empty legacy PM callbacks from a couple of PCI drivers. - Suspend-to-both for in-kernel hibernation from Bojan Smojver. - cpuidle fixes and cleanups from ShuoX Liu, Daniel Lezcano and Preeti Murthy. - cpufreq bug fixes from Jonghwa Lee and Stephen Boyd. - Suspend and hibernate fixes from Srivatsa Bhat and Colin Cross. - Generic PM domains framework updates. - RTC CMOS wakeup signaling update from Paul Fox. - sparse warnings fixes from Sachin Kamat. - Build warnings fixes for the generic PM domains framework and PM sysfs code. - sysfs switch for printing device suspend times from Sameer Nanda. - Documentation fix from Oskar Schirmer. * tag 'pm-for-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (70 commits) cpufreq: Fix sysfs deadlock with concurrent hotplug/frequency switch EXYNOS: bugfix on retrieving old_index from freqs.old PM / Sleep: call early resume handlers when suspend_noirq fails PM / QoS: Use NULL pointer instead of plain integer in qos.c PM / QoS: Use NULL pointer instead of plain integer in pm_qos.h PM / Sleep: Require CAP_BLOCK_SUSPEND to use wake_lock/wake_unlock PM / Sleep: Add missing static storage class specifiers in main.c cpuilde / ACPI: remove time from acpi_processor_cx structure cpuidle / ACPI: remove usage from acpi_processor_cx structure cpuidle / ACPI : remove latency_ticks from acpi_processor_cx structure rtc-cmos: report wakeups from interrupt handler PM / Sleep: Fix build warning in sysfs.c for CONFIG_PM_SLEEP unset PM / Domains: Fix build warning for CONFIG_PM_RUNTIME unset olpc-xo15-sci: Use struct dev_pm_ops for power management PM / Domains: Replace plain integer with NULL pointer in domain.c file PM / Domains: Add missing static storage class specifier in domain.c file PM / crypto / ux500: Use struct dev_pm_ops for power management PM / IPMI: Remove empty legacy PCI PM callbacks tpm_nsc: Use struct dev_pm_ops for power management tpm_tis: Use struct dev_pm_ops for power management ...

Make wait_for_device_probe() also do scsi_complete_async_scans()

2012-07-19T01:15:46Z

Commit a7a20d103994 ("sd: limit the scope of the async probe domain") make the SCSI device probing run device discovery in it's own async domain. However, as a result, the partition detection was no longer synchronized by async_synchronize_full() (which, despite the name, only synchronizes the global async space, not all of them). Which in turn meant that "wait_for_device_probe()" would not wait for the SCSI partitions to be parsed. And "wait_for_device_probe()" was what the boot time init code relied on for mounting the root filesystem. Now, most people never noticed this, because not only is it timing-dependent, but modern distributions all use initrd. So the root filesystem isn't actually on a disk at all. And then before they actually mount the final disk filesystem, they will have loaded the scsi-wait-scan module, which not only does the expected wait_for_device_probe(), but also does scsi_complete_async_scans(). [ Side note: scsi_complete_async_scans() had also been partially broken, but that was fixed in commit 43a8d39d0137 ("fix async probe regression"), so that same commit a7a20d103994 had actually broken setups even if you used scsi-wait-scan explicitly ] Solve this problem by just moving the scsi_complete_async_scans() call into wait_for_device_probe(). Everybody who wants to wait for device probing to finish really wants the SCSI probing to complete, so there's no reason not to do this. So now "wait_for_device_probe()" really does what the name implies, and properly waits for device probing to finish. This also removes the now unnecessary extra calls to scsi_complete_async_scans(). Reported-and-tested-by: Artem S. Tashkinov Cc: Dan Williams Cc: Alan Stern Cc: James Bottomley Cc: Borislav Petkov Cc: linux-scsi Signed-off-by: Linus Torvalds

PM / Sleep: Require CAP_BLOCK_SUSPEND to use wake_lock/wake_unlock

2012-07-18T22:00:58Z

Require processes wanting to use the wake_lock/wake_unlock sysfs files to have the CAP_BLOCK_SUSPEND capability, which also is required for the eventpoll EPOLLWAKEUP flag to be effective, so that all interfaces related to blocking autosleep depend on the same capability. Signed-off-by: Rafael J. Wysocki Cc: stable@vger.kernel.org Acked-by: Michael Kerrisk

PM / Hibernate: Print hibernation/thaw progress indicator one line at a time.

2012-07-01T11:31:23Z

With the introduction of suspend to both into in-kernel hibernation code, dmesg was getting polluted with backspace characters printed as part of image saving progress indicator. This patch introduces printing of progress indicator on image save/load every 10% and one line at a time. As an additional benefit, all other messages emitted by the kernel during hibernation/thaw should now print cleanly as well. Signed-off-by: Bojan Smojver Signed-off-by: Rafael J. Wysocki

PM / Sleep: Separate printing suspend times from initcall_debug

2012-07-01T11:31:23Z

Change the behavior of the newly introduced /sys/power/pm_print_times attribute so that its initial value depends on initcall_debug, but setting it to 0 will cause device suspend/resume times not to be printed, even if initcall_debug has been set. This way, the people who use initcall_debug for reasons other than PM debugging will be able to switch the suspend/resume times printing off, if need be. Signed-off-by: Rafael J. Wysocki Reviewed-by: Srivatsa S. Bhat Acked-by: Greg Kroah-Hartman

PM / Sleep: add knob for printing device resume times

2012-07-01T11:31:22Z

Added a new knob called /sys/power/pm_print_times. Setting it to 1 enables printing of time taken by devices to suspend and resume. Setting it to 0 disables this printing (unless overridden by initcall_debug kernel command line option). Signed-off-by: Sameer Nanda Acked-by: Greg KH Signed-off-by: Rafael J. Wysocki

ftrace: Disable function tracing during suspend/resume and hibernation, again

2012-07-01T11:31:22Z

If function tracing is enabled for some of the low-level suspend/resume functions, it leads to triple fault during resume from suspend, ultimately ending up in a reboot instead of a resume (or a total refusal to come out of suspended state, on some machines). This issue was explained in more detail in commit f42ac38c59e0a03d (ftrace: disable tracing for suspend to ram). However, the changes made by that commit got reverted by commit cbe2f5a6e84eebb (tracing: allow tracing of suspend/resume & hibernation code again). So, unfortunately since things are not yet robust enough to allow tracing of low-level suspend/resume functions, suspend/resume is still broken when ftrace is enabled. So fix this by disabling function tracing during suspend/resume & hibernation. Signed-off-by: Srivatsa S. Bhat Cc: stable@vger.kernel.org Signed-off-by: Rafael J. Wysocki

PM / Hibernate: Enable suspend to both for in-kernel hibernation.

2012-07-01T11:31:22Z

It is often useful to suspend to memory after hibernation image has been written to disk. If the battery runs out or power is otherwise lost, the computer will resume from the hibernated image. If not, it will resume from memory and hibernation image will be discarded. Signed-off-by: Bojan Smojver Signed-off-by: Rafael J. Wysocki