user/sven/linux.git/kernel/power, branch v3.4.67

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

2012-08-09T15:31:29Z

commit 443772d408a25af62498793f6f805ce3c559309a upstream. 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 Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM / Hibernate: fix the number of pages used for hibernate/thaw buffering

2012-04-24T21:53:28Z

Hibernation regression fix, since 3.2. Calculate the number of required free pages based on non-high memory pages only, because that is where the buffers will come from. Commit 081a9d043c983f161b78fdc4671324d1342b86bc introduced a new buffer page allocation logic during hibernation, in order to improve the performance. The amount of pages allocated was calculated based on total amount of pages available, although only non-high memory pages are usable for this purpose. This caused hibernation code to attempt to over allocate pages on platforms that have high memory, which led to hangs. Signed-off-by: Bojan Smojver Signed-off-by: Rafael J. Wysocki

PM / QoS: add pm_qos_update_request_timeout() API

2012-03-28T21:31:24Z

The new API, pm_qos_update_request_timeout() is to provide a timeout with pm_qos_update_request. For example, pm_qos_update_request_timeout(req, 100, 1000), means that QoS request on req with value 100 will be active for 1000 microseconds. After 1000 microseconds, the QoS request thru req is reset. If there were another pm_qos_update_request(req, x) during the 1000 us, this new request with value x will override as this is another request on the same req handle. A new request on the same req handle will always override the previous request whether it is the conventional request or it is the new timeout request. Signed-off-by: MyungJoo Ham Signed-off-by: Kyungmin Park Acked-by: Mark Gross Signed-off-by: Rafael J. Wysocki

PM / Sleep: Mitigate race between the freezer and request_firmware()

2012-03-28T21:30:28Z

There is a race condition between the freezer and request_firmware() such that if request_firmware() is run on one CPU and freeze_processes() is run on another CPU and usermodehelper_disable() called by it succeeds to grab umhelper_sem for writing before usermodehelper_read_trylock() called from request_firmware() acquires it for reading, the request_firmware() will fail and trigger a WARN_ON() complaining that it was called at a wrong time. However, in fact, it wasn't called at a wrong time and freeze_processes() simply happened to be executed simultaneously. To avoid this race, at least in some cases, modify usermodehelper_read_trylock() so that it doesn't fail if the freezing of tasks has just started and hasn't been completed yet. Instead, during the freezing of tasks, it will try to freeze the task that has called it so that it can wait until user space is thawed without triggering the scary warning. For this purpose, change usermodehelper_disabled so that it can take three different values, UMH_ENABLED (0), UMH_FREEZING and UMH_DISABLED. The first one means that usermode helpers are enabled, the last one means "hard disable" (i.e. the system is not ready for usermode helpers to be used) and the second one is reserved for the freezer. Namely, when freeze_processes() is started, it sets usermodehelper_disabled to UMH_FREEZING which tells usermodehelper_read_trylock() that it shouldn't fail just yet and should call try_to_freeze() if woken up and cannot return immediately. This way all freezable tasks that happen to call request_firmware() right before freeze_processes() is started and lose the race for umhelper_sem with it will be frozen and will sleep until thaw_processes() unsets usermodehelper_disabled. [For the non-freezable callers of request_firmware() the race for umhelper_sem against freeze_processes() is unfortunately unavoidable.] Reported-by: Stephen Boyd Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Cc: stable@vger.kernel.org

PM / Sleep: Move disabling of usermode helpers to the freezer

2012-03-28T21:30:21Z

The core suspend/hibernation code calls usermodehelper_disable() to avoid race conditions between the freezer and the starting of usermode helpers and each code path has to do that on its own. However, it is always called right before freeze_processes() and usermodehelper_enable() is always called right after thaw_processes(). For this reason, to avoid code duplication and to make the connection between usermodehelper_disable() and the freezer more visible, make freeze_processes() call it and remove the direct usermodehelper_disable() and usermodehelper_enable() calls from all suspend/hibernation code paths. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Cc: stable@vger.kernel.org

PM / Hibernate: Disable usermode helpers right before freezing tasks

2012-03-28T21:30:14Z

There is no reason to call usermodehelper_disable() before creating memory bitmaps in hibernate() and software_resume(), so call it right before freeze_processes(), in accordance with the other suspend and hibernation code. Consequently, call usermodehelper_enable() right after the thawing of tasks rather than after freeing the memory bitmaps. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Cc: stable@vger.kernel.org

Merge tag 'pm-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2012-03-21T17:15:51Z

Pull power management updates for 3.4 from Rafael Wysocki: "Assorted extensions and fixes including: * Introduction of early/late suspend/hibernation device callbacks. * Generic PM domains extensions and fixes. * devfreq updates from Axel Lin and MyungJoo Ham. * Device PM QoS updates. * Fixes of concurrency problems with wakeup sources. * System suspend and hibernation fixes." * tag 'pm-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (43 commits) PM / Domains: Check domain status during hibernation restore of devices PM / devfreq: add relation of recommended frequency. PM / shmobile: Make MTU2 driver use pm_genpd_dev_always_on() PM / shmobile: Make CMT driver use pm_genpd_dev_always_on() PM / shmobile: Make TMU driver use pm_genpd_dev_always_on() PM / Domains: Introduce "always on" device flag PM / Domains: Fix hibernation restore of devices, v2 PM / Domains: Fix handling of wakeup devices during system resume sh_mmcif / PM: Use PM QoS latency constraint tmio_mmc / PM: Use PM QoS latency constraint PM / QoS: Make it possible to expose PM QoS latency constraints PM / Sleep: JBD and JBD2 missing set_freezable() PM / Domains: Fix include for PM_GENERIC_DOMAINS=n case PM / Freezer: Remove references to TIF_FREEZE in comments PM / Sleep: Add more wakeup source initialization routines PM / Hibernate: Enable usermodehelpers in hibernate() error path PM / Sleep: Make __pm_stay_awake() delete wakeup source timers PM / Sleep: Fix race conditions related to wakeup source timer function PM / Sleep: Fix possible infinite loop during wakeup source destruction PM / Hibernate: print physical addresses consistently with other parts of kernel ...

power: remove the second argument of k[un]map_atomic()

2012-03-20T13:48:26Z

Acked-by: Rafael J. Wysocki Signed-off-by: Cong Wang

Merge branch 'pm-qos'

2012-03-04T22:11:24Z

* pm-qos: PM / QoS: unconditionally build the feature PM / QoS: Simplify PM QoS expansion/merge

PM / Freezer: Remove references to TIF_FREEZE in comments

2012-03-04T22:08:54Z

This patch removes all the references in the code about the TIF_FREEZE flag removed by commit a3201227f803ad7fd43180c5195dbe5a2bf998aa freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE There still are some references to TIF_FREEZE in Documentation/power/freezing-of-tasks.txt, but it looks like that documentation needs more thorough work to reflect how the new freezer works, and hence merely removing the references to TIF_FREEZE won't really help. So I have not touched that part in this patch. Suggested-by: Srivatsa S. Bhat Signed-off-by: Marcos Paulo de Souza Signed-off-by: Rafael J. Wysocki