linux/drivers/base/power, branch v4.8

PM / runtime: Use _rcuidle for runtime suspend tracepoints

2016-09-16T00:59:58Z

Further testing with false negatives suppressed by commit 293e2421fe25 ("rcu: Remove superfluous versions of rcu_read_lock_sched_held()") identified a few more unprotected uses of RCU from the idle loop. Because RCU actively ignores idle-loop code (for energy-efficiency reasons, among other things), using RCU from the idle loop can result in too-short grace periods, in turn resulting in arbitrary misbehavior. The affected function is rpm_suspend(). The resulting lockdep-RCU splat is as follows: ------------------------------------------------------------------------ Warning from omap3 =============================== [ INFO: suspicious RCU usage. ] 4.6.0-rc5-next-20160426+ #1112 Not tainted ------------------------------- include/trace/events/rpm.h:63 suspicious rcu_dereference_check() usage! other info that might help us debug this: RCU used illegally from idle CPU! rcu_scheduler_active = 1, debug_locks = 0 RCU used illegally from extended quiescent state! 1 lock held by swapper/0/0: #0: (&(&dev->power.lock)->rlock){-.-...}, at: [] __pm_runtime_suspend+0x54/0x84 stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.6.0-rc5-next-20160426+ #1112 Hardware name: Generic OMAP36xx (Flattened Device Tree) [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (dump_stack+0xb0/0xe4) [] (dump_stack) from [] (rpm_suspend+0x604/0x7e4) [] (rpm_suspend) from [] (__pm_runtime_suspend+0x64/0x84) [] (__pm_runtime_suspend) from [] (omap2_gpio_prepare_for_idle+0x5c/0x70) [] (omap2_gpio_prepare_for_idle) from [] (omap_sram_idle+0x140/0x244) [] (omap_sram_idle) from [] (omap3_enter_idle_bm+0xfc/0x1ec) [] (omap3_enter_idle_bm) from [] (cpuidle_enter_state+0x80/0x3d4) [] (cpuidle_enter_state) from [] (cpu_startup_entry+0x198/0x3a0) [] (cpu_startup_entry) from [] (start_kernel+0x354/0x3c8) [] (start_kernel) from [<8000807c>] (0x8000807c) ------------------------------------------------------------------------ Reported-by: Tony Lindgren Signed-off-by: Paul E. McKenney Tested-by: Tony Lindgren Tested-by: Guenter Roeck [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki

PM / runtime: Add _rcuidle suffix to allow rpm_idle() use from idle

2016-08-31T01:00:59Z

This commit appends a few _rcuidle suffixes to fix the following RCU-used-from-idle bug: > =============================== > [ INFO: suspicious RCU usage. ] > 4.6.0-rc5-next-20160426+ #1116 Not tainted > ------------------------------- > include/trace/events/rpm.h:95 suspicious rcu_dereference_check() usage! > > other info that might help us debug this: > > > RCU used illegally from idle CPU! > rcu_scheduler_active = 1, debug_locks = 0 > RCU used illegally from extended quiescent state! > 1 lock held by swapper/0/0: > #0: (&(&dev->power.lock)->rlock){-.-...}, at: [] __rpm_callback+0x58/0x60 > > stack backtrace: > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.6.0-rc5-next-20160426+ #1116 > Hardware name: Generic OMAP36xx (Flattened Device Tree) > [] (unwind_backtrace) from [] (show_stack+0x10/0x14) > [] (show_stack) from [] (dump_stack+0xb0/0xe4) > [] (dump_stack) from [] (rpm_suspend+0x580/0x768) > [] (rpm_suspend) from [] (__pm_runtime_suspend+0x64/0x84) > [] (__pm_runtime_suspend) from [] (omap2_gpio_prepare_for_idle+0x5c/0x70) > [] (omap2_gpio_prepare_for_idle) from [] (omap_sram_idle+0x140/0x244) > [] (omap_sram_idle) from [] (omap3_enter_idle_bm+0xfc/0x1ec) > [] (omap3_enter_idle_bm) from [] (cpuidle_enter_state+0x80/0x3d4) > [] (cpuidle_enter_state) from [] (cpu_startup_entry+0x198/0x3a0) > [] (cpu_startup_entry) from [] (start_kernel+0x354/0x3c8) > [] (start_kernel) from [<8000807c>] (0x8000807c) In the immortal words of Steven Rostedt, "*Whack* *Whack* *Whack*!!!" Reported-by: Tony Lindgren Signed-off-by: Paul E. McKenney Tested-by: Tony Lindgren Tested-by: Guenter Roeck WhACKED-by: Steven Rostedt Signed-off-by: Rafael J. Wysocki

PM / runtime: Add _rcuidle suffix to allow rpm_resume() to be called from idle

2016-08-31T00:59:20Z

This commit applies another _rcuidle suffix to fix an RCU use from idle. > =============================== > [ INFO: suspicious RCU usage. ] > 4.6.0-rc5-next-20160426+ #1122 Not tainted > ------------------------------- > include/trace/events/rpm.h:69 suspicious rcu_dereference_check() usage! > > other info that might help us debug this: > > > RCU used illegally from idle CPU! > rcu_scheduler_active = 1, debug_locks = 0 > RCU used illegally from extended quiescent state! > 1 lock held by swapper/0/0: > #0: (&(&dev->power.lock)->rlock){-.-...}, at: [] __pm_runtime_resume+0x3c/0x64 > > stack backtrace: > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.6.0-rc5-next-20160426+ #1122 > Hardware name: Generic OMAP36xx (Flattened Device Tree) > [] (unwind_backtrace) from [] (show_stack+0x10/0x14) > [] (show_stack) from [] (dump_stack+0xb0/0xe4) > [] (dump_stack) from [] (rpm_resume+0x5cc/0x7f4) > [] (rpm_resume) from [] (__pm_runtime_resume+0x4c/0x64) > [] (__pm_runtime_resume) from [] (omap2_gpio_resume_after_idle+0x54/0x68) > [] (omap2_gpio_resume_after_idle) from [] (omap3_enter_idle_bm+0xfc/0x1ec) > [] (omap3_enter_idle_bm) from [] (cpuidle_enter_state+0x80/0x3d4) > [] (cpuidle_enter_state) from [] (cpu_startup_entry+0x198/0x3a0) > [] (cpu_startup_entry) from [] (start_kernel+0x354/0x3c8) > [] (start_kernel) from [<8000807c>] (0x8000807c) Reported-by: Tony Lindgren Signed-off-by: Paul E. McKenney Tested-by: Tony Lindgren Tested-by: Guenter Roeck Signed-off-by: Rafael J. Wysocki

Merge tag 'pm-extra-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2016-08-06T03:26:16Z

Pull more power management updates from Rafael Wysocki: "A few more fixes and cleanups in the x86-64 low-level hibernation code, PM core, cpufreq (Kconfig and intel_pstate), and the operating points framework. Specifics: - Prevent the low-level assembly hibernate code on x86-64 from referring to __PAGE_OFFSET directly as a symbol which doesn't work when the kernel identity mapping base is randomized, in which case __PAGE_OFFSET is a variable (Rafael Wysocki). - Avoid selecting CPU_FREQ_STAT by default as the statistics are not required for proper cpufreq operation (Borislav Petkov). - Add Skylake-X and Broadwell-X IDs to the intel_pstate's list of processors where out-of-band (OBB) control of P-states is possible and if that is in use, intel_pstate should not attempt to manage P-states (Srinivas Pandruvada). - Drop some unnecessary checks from the wakeup IRQ handling code in the PM core (Markus Elfring). - Reduce the number operating performance point (OPP) lookups in one of the OPP framework's helper functions (Jisheng Zhang)" * tag 'pm-extra-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: x86/power/64: Do not refer to __PAGE_OFFSET from assembly code cpufreq: Do not default-yes CPU_FREQ_STAT cpufreq: intel_pstate: Add more out-of-band IDs PM / OPP: optimize dev_pm_opp_set_rate() performance a bit PM-wakeup: Delete unnecessary checks before three function calls

Merge tag 'rtc-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

2016-08-05T13:48:22Z

Pull RTC updates from Alexandre Belloni: "RTC for 4.8 Cleanups: - huge cleanup of rtc-generic and char/genrtc this allowed to cleanup rtc-cmos, rtc-sh, rtc-m68k, rtc-powerpc and rtc-parisc - move mn10300 to rtc-cmos Subsystem: - fix wakealarms after hibernate - multiples fixes for rctest - simplify implementations of .read_alarm New drivers: - Maxim MAX6916 Drivers: - ds1307: fix weekday - m41t80: add wakeup support - pcf85063: add support for PCF85063A variant - rv8803: extend i2c fix and other fixes - s35390a: fix alarm reading, this fixes instant reboot after shutdown for QNAP TS-41x - s3c: clock fixes" * tag 'rtc-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (65 commits) rtc: rv8803: Clear V1F when setting the time rtc: rv8803: Stop the clock while setting the time rtc: rv8803: Always apply the I²C workaround rtc: rv8803: Fix read day of week rtc: rv8803: Remove the check for valid time rtc: rv8803: Kconfig: Indicate rx8900 support rtc: asm9260: remove .owner field for driver rtc: at91sam9: Fix missing spin_lock_init() rtc: m41t80: add suspend handlers for alarm IRQ rtc: m41t80: make it a real error message rtc: pcf85063: Add support for the PCF85063A device rtc: pcf85063: fix year range rtc: hym8563: in .read_alarm set .tm_sec to 0 to signal minute accuracy rtc: explicitly set tm_sec = 0 for drivers with minute accurancy rtc: s3c: Add s3c_rtc_{enable/disable}_clk in s3c_rtc_setfreq() rtc: s3c: Remove unnecessary call to disable already disabled clock rtc: abx80x: use devm_add_action_or_reset() rtc: m41t80: use devm_add_action_or_reset() rtc: fix a typo and reduce three empty lines to one rtc: s35390a: improve two comments in .set_alarm ...

Merge branches 'pm-sleep', 'pm-cpufreq', 'pm-core' and 'pm-opp'

2016-08-05T13:46:55Z

* pm-sleep: x86/power/64: Do not refer to __PAGE_OFFSET from assembly code * pm-cpufreq: cpufreq: Do not default-yes CPU_FREQ_STAT cpufreq: intel_pstate: Add more out-of-band IDs * pm-core: PM-wakeup: Delete unnecessary checks before three function calls * pm-opp: PM / OPP: optimize dev_pm_opp_set_rate() performance a bit

PM / OPP: optimize dev_pm_opp_set_rate() performance a bit

2016-07-28T21:54:16Z

In dev_pm_opp_set_rate(), _find_opp_table() is called 4 times: once by _get_opp_clk(), once by dev_pm_opp_set_rate() itself, and twice by dev_pm_opp_find_freq_ceil(). If there are several opp_tables in the system, three times of opp table finding is a big waste. This patch reduced the call of _find_opp_table() to twice. Signed-off-by: Jisheng Zhang Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki

PM-wakeup: Delete unnecessary checks before three function calls

2016-07-28T21:51:04Z

The following functions test whether their argument is NULL and then return immediately. * dev_pm_arm_wake_irq * dev_pm_disarm_wake_irq * wakeup_source_unregister Thus the test around the calls is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring Acked-by: Pavel Machek [ rjw: Minor whitespace adjustments ] Signed-off-by: Rafael J. Wysocki

Merge branches 'pm-core', 'pm-clk', 'pm-domains' and 'pm-pci'

2016-07-25T11:45:27Z

* pm-core: PM / runtime: Asynchronous "idle" in pm_runtime_allow() PM / runtime: print error when activating a child to unactive parent * pm-clk: PM / clk: Add support for adding a specific clock from device-tree PM / clk: export symbols for existing pm_clk_<...> API fcns * pm-domains: PM / Domains: Convert pm_genpd_init() to return an error code PM / Domains: Stop/start devices during system PM suspend/resume in genpd PM / Domains: Allow runtime PM during system PM phases PM / Runtime: Avoid resuming devices again in pm_runtime_force_resume() PM / Domains: Remove redundant pm_request_idle() call in genpd PM / Domains: Remove redundant wrapper functions for system PM PM / Domains: Allow genpd to power on during system PM phases * pm-pci: PCI / PM: check all fields in pci_set_platform_pm()

PM / runtime: Asynchronous "idle" in pm_runtime_allow()

2016-07-01T23:50:39Z

Arjan reports that it takes a relatively long time to enable runtime PM for multiple devices at system startup, because all writes to the "control" attribute in sysfs are handled synchronously and if the device is suspended as a result of the write, it will block until that operation is complete. That may be avoided by passing the RPM_ASYNC flag to rpm_idle() in pm_runtime_allow() which will make it execute the device's "idle" callback asynchronously, so writes to "control" changing it from "on" to "auto" will return without waiting. Reported-by: Arjan van de Ven Signed-off-by: Rafael J. Wysocki Acked-by: Alan Stern Reviewed-by: Ulf Hansson Reviewed-by: Kevin Hilman