linux-dev/drivers/base/power/main.c, branch linus/master

Merge branches 'pm-sleep', 'pm-domains' and 'pm-docs'

2022-03-18T17:29:21Z

Merge changes related to system sleep, PM domains changes and power management documentation changes for 5.18-rc1: - Fix load_image_and_restore() error path (Ye Bin). - Fix typos in comments in the system wakeup hadling code (Tom Rix). - Clean up non-kernel-doc comments in hibernation code (Jiapeng Chong). - Fix __setup handler error handling in system-wide suspend and hibernation core code (Randy Dunlap). - Add device name to suspend_report_result() (Youngjin Jang). - Make virtual guests honour ACPI S4 hardware signature by default (David Woodhouse). - Block power off of a parent PM domain unless child is in deepest state (Ulf Hansson). - Use dev_err_probe() to simplify error handling for generic PM domains (Ahmad Fatoum). - Fix sleep-in-atomic bug caused by genpd_debug_remove() (Shawn Guo). - Document Intel uncore frequency scaling (Srinivas Pandruvada). * pm-sleep: PM: hibernate: Honour ACPI hardware signature by default for virtual guests PM: sleep: Add device name to suspend_report_result() PM: suspend: fix return value of __setup handler PM: hibernate: fix __setup handler error handling PM: hibernate: Clean up non-kernel-doc comments PM: sleep: wakeup: Fix typos in comments PM: hibernate: fix load_image_and_restore() error path * pm-domains: PM: domains: Fix sleep-in-atomic bug caused by genpd_debug_remove() PM: domains: use dev_err_probe() to simplify error handling PM: domains: Prevent power off for parent unless child is in deepest state * pm-docs: Documentation: admin-guide: pm: Document uncore frequency scaling

PM: core: keep irq flags in device_pm_check_callbacks()

2022-03-10T18:40:15Z

The function device_pm_check_callbacks() can be called under the spin lock (in the reported case it happens from genpd_add_device() -> dev_pm_domain_set(), when the genpd uses spinlocks rather than mutexes. However this function uncoditionally uses spin_lock_irq() / spin_unlock_irq(), thus not preserving the CPU flags. Use the irqsave/irqrestore instead. The backtrace for the reference: [ 2.752010] ------------[ cut here ]------------ [ 2.756769] raw_local_irq_restore() called with IRQs enabled [ 2.762596] WARNING: CPU: 4 PID: 1 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x34/0x50 [ 2.772338] Modules linked in: [ 2.775487] CPU: 4 PID: 1 Comm: swapper/0 Tainted: G S 5.17.0-rc6-00384-ge330d0d82eff-dirty #684 [ 2.781384] Freeing initrd memory: 46024K [ 2.785839] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 2.785841] pc : warn_bogus_irq_restore+0x34/0x50 [ 2.785844] lr : warn_bogus_irq_restore+0x34/0x50 [ 2.785846] sp : ffff80000805b7d0 [ 2.785847] x29: ffff80000805b7d0 x28: 0000000000000000 x27: 0000000000000002 [ 2.785850] x26: ffffd40e80930b18 x25: ffff7ee2329192b8 x24: ffff7edfc9f60800 [ 2.785853] x23: ffffd40e80930b18 x22: ffffd40e80930d30 x21: ffff7edfc0dffa00 [ 2.785856] x20: ffff7edfc09e3768 x19: 0000000000000000 x18: ffffffffffffffff [ 2.845775] x17: 6572206f74206465 x16: 6c696166203a3030 x15: ffff80008805b4f7 [ 2.853108] x14: 0000000000000000 x13: ffffd40e809550b0 x12: 00000000000003d8 [ 2.860441] x11: 0000000000000148 x10: ffffd40e809550b0 x9 : ffffd40e809550b0 [ 2.867774] x8 : 00000000ffffefff x7 : ffffd40e809ad0b0 x6 : ffffd40e809ad0b0 [ 2.875107] x5 : 000000000000bff4 x4 : 0000000000000000 x3 : 0000000000000000 [ 2.882440] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff7edfc03a8000 [ 2.889774] Call trace: [ 2.892290] warn_bogus_irq_restore+0x34/0x50 [ 2.896770] _raw_spin_unlock_irqrestore+0x94/0xa0 [ 2.901690] genpd_unlock_spin+0x20/0x30 [ 2.905724] genpd_add_device+0x100/0x2d0 [ 2.909850] __genpd_dev_pm_attach+0xa8/0x23c [ 2.914329] genpd_dev_pm_attach_by_id+0xc4/0x190 [ 2.919167] genpd_dev_pm_attach_by_name+0x3c/0xd0 [ 2.924086] dev_pm_domain_attach_by_name+0x24/0x30 [ 2.929102] psci_dt_attach_cpu+0x24/0x90 [ 2.933230] psci_cpuidle_probe+0x2d4/0x46c [ 2.937534] platform_probe+0x68/0xe0 [ 2.941304] really_probe.part.0+0x9c/0x2fc [ 2.945605] __driver_probe_device+0x98/0x144 [ 2.950085] driver_probe_device+0x44/0x15c [ 2.954385] __device_attach_driver+0xb8/0x120 [ 2.958950] bus_for_each_drv+0x78/0xd0 [ 2.962896] __device_attach+0xd8/0x180 [ 2.966843] device_initial_probe+0x14/0x20 [ 2.971144] bus_probe_device+0x9c/0xa4 [ 2.975092] device_add+0x380/0x88c [ 2.978679] platform_device_add+0x114/0x234 [ 2.983067] platform_device_register_full+0x100/0x190 [ 2.988344] psci_idle_init+0x6c/0xb0 [ 2.992113] do_one_initcall+0x74/0x3a0 [ 2.996060] kernel_init_freeable+0x2fc/0x384 [ 3.000543] kernel_init+0x28/0x130 [ 3.004132] ret_from_fork+0x10/0x20 [ 3.007817] irq event stamp: 319826 [ 3.011404] hardirqs last enabled at (319825): [] __up_console_sem+0x78/0x84 [ 3.020332] hardirqs last disabled at (319826): [] el1_dbg+0x24/0x8c [ 3.028458] softirqs last enabled at (318312): [] _stext+0x410/0x588 [ 3.036678] softirqs last disabled at (318299): [] __irq_exit_rcu+0x158/0x174 [ 3.045607] ---[ end trace 0000000000000000 ]--- Signed-off-by: Dmitry Baryshkov Signed-off-by: Rafael J. Wysocki

PM: sleep: Add device name to suspend_report_result()

2022-03-08T18:57:01Z

Currently, suspend_report_result() prints only function information. If any driver uses a common PM function, nobody knows who exactly called the failing function. A device pinter is needed to recognize the failing device. For example: PM: dpm_run_callback(): pnp_bus_suspend+0x0/0x10 returns 0 PM: dpm_run_callback(): pci_pm_suspend+0x0/0x150 returns 0 become after the change: serial 00:05: PM: dpm_run_callback(): pnp_bus_suspend+0x0/0x10 returns 0 pci 0000:00:01.3: PM: dpm_run_callback(): pci_pm_suspend+0x0/0x150 returns 0 Signed-off-by: Youngjin Jang [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki

PM: sleep: Fix error handling in dpm_prepare()

2021-12-17T17:36:08Z

Commit 2aa36604e824 ("PM: sleep: Avoid calling put_device() under dpm_list_mtx") forgot to update the while () loop termination condition to also break the loop if error is nonzero, which causes the loop to become infinite if device_prepare() returns an error for one device. Add the missing !error check. Fixes: 2aa36604e824 ("PM: sleep: Avoid calling put_device() under dpm_list_mtx") Signed-off-by: Rafael J. Wysocki Reported-by: Thomas Hellström Reviewed-by: Thomas Hellström Reviewed-by: Ulf Hansson Cc: All applicable

PM: sleep: Avoid calling put_device() under dpm_list_mtx

2021-11-05T15:10:11Z

It is generally unsafe to call put_device() with dpm_list_mtx held, because the given device's release routine may carry out an action depending on that lock which then may deadlock, so modify the system-wide suspend and resume of devices to always drop dpm_list_mtx before calling put_device() (and adjust white space somewhat while at it). For instance, this prevents the following splat from showing up in the kernel log after a system resume in certain configurations: [ 3290.969514] ====================================================== [ 3290.969517] WARNING: possible circular locking dependency detected [ 3290.969519] 5.15.0+ #2420 Tainted: G S [ 3290.969523] ------------------------------------------------------ [ 3290.969525] systemd-sleep/4553 is trying to acquire lock: [ 3290.969529] ffff888117ab1138 ((wq_completion)hci0#2){+.+.}-{0:0}, at: flush_workqueue+0x87/0x4a0 [ 3290.969554] but task is already holding lock: [ 3290.969556] ffffffff8280fca8 (dpm_list_mtx){+.+.}-{3:3}, at: dpm_resume+0x12e/0x3e0 [ 3290.969571] which lock already depends on the new lock. [ 3290.969573] the existing dependency chain (in reverse order) is: [ 3290.969575] -> #3 (dpm_list_mtx){+.+.}-{3:3}: [ 3290.969583] __mutex_lock+0x9d/0xa30 [ 3290.969591] device_pm_add+0x2e/0xe0 [ 3290.969597] device_add+0x4d5/0x8f0 [ 3290.969605] hci_conn_add_sysfs+0x43/0xb0 [bluetooth] [ 3290.969689] hci_conn_complete_evt.isra.71+0x124/0x750 [bluetooth] [ 3290.969747] hci_event_packet+0xd6c/0x28a0 [bluetooth] [ 3290.969798] hci_rx_work+0x213/0x640 [bluetooth] [ 3290.969842] process_one_work+0x2aa/0x650 [ 3290.969851] worker_thread+0x39/0x400 [ 3290.969859] kthread+0x142/0x170 [ 3290.969865] ret_from_fork+0x22/0x30 [ 3290.969872] -> #2 (&hdev->lock){+.+.}-{3:3}: [ 3290.969881] __mutex_lock+0x9d/0xa30 [ 3290.969887] hci_event_packet+0xba/0x28a0 [bluetooth] [ 3290.969935] hci_rx_work+0x213/0x640 [bluetooth] [ 3290.969978] process_one_work+0x2aa/0x650 [ 3290.969985] worker_thread+0x39/0x400 [ 3290.969993] kthread+0x142/0x170 [ 3290.969999] ret_from_fork+0x22/0x30 [ 3290.970004] -> #1 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}: [ 3290.970013] process_one_work+0x27d/0x650 [ 3290.970020] worker_thread+0x39/0x400 [ 3290.970028] kthread+0x142/0x170 [ 3290.970033] ret_from_fork+0x22/0x30 [ 3290.970038] -> #0 ((wq_completion)hci0#2){+.+.}-{0:0}: [ 3290.970047] __lock_acquire+0x15cb/0x1b50 [ 3290.970054] lock_acquire+0x26c/0x300 [ 3290.970059] flush_workqueue+0xae/0x4a0 [ 3290.970066] drain_workqueue+0xa1/0x130 [ 3290.970073] destroy_workqueue+0x34/0x1f0 [ 3290.970081] hci_release_dev+0x49/0x180 [bluetooth] [ 3290.970130] bt_host_release+0x1d/0x30 [bluetooth] [ 3290.970195] device_release+0x33/0x90 [ 3290.970201] kobject_release+0x63/0x160 [ 3290.970211] dpm_resume+0x164/0x3e0 [ 3290.970215] dpm_resume_end+0xd/0x20 [ 3290.970220] suspend_devices_and_enter+0x1a4/0xba0 [ 3290.970229] pm_suspend+0x26b/0x310 [ 3290.970236] state_store+0x42/0x90 [ 3290.970243] kernfs_fop_write_iter+0x135/0x1b0 [ 3290.970251] new_sync_write+0x125/0x1c0 [ 3290.970257] vfs_write+0x360/0x3c0 [ 3290.970263] ksys_write+0xa7/0xe0 [ 3290.970269] do_syscall_64+0x3a/0x80 [ 3290.970276] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3290.970284] other info that might help us debug this: [ 3290.970285] Chain exists of: (wq_completion)hci0#2 --> &hdev->lock --> dpm_list_mtx [ 3290.970297] Possible unsafe locking scenario: [ 3290.970299] CPU0 CPU1 [ 3290.970300] ---- ---- [ 3290.970302] lock(dpm_list_mtx); [ 3290.970306] lock(&hdev->lock); [ 3290.970310] lock(dpm_list_mtx); [ 3290.970314] lock((wq_completion)hci0#2); [ 3290.970319] *** DEADLOCK *** [ 3290.970321] 7 locks held by systemd-sleep/4553: [ 3290.970325] #0: ffff888103bcd448 (sb_writers#4){.+.+}-{0:0}, at: ksys_write+0xa7/0xe0 [ 3290.970341] #1: ffff888115a14488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x103/0x1b0 [ 3290.970355] #2: ffff888100f719e0 (kn->active#233){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x10c/0x1b0 [ 3290.970369] #3: ffffffff82661048 (autosleep_lock){+.+.}-{3:3}, at: state_store+0x12/0x90 [ 3290.970384] #4: ffffffff82658ac8 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend+0x9f/0x310 [ 3290.970399] #5: ffffffff827f2a48 (acpi_scan_lock){+.+.}-{3:3}, at: acpi_suspend_begin+0x4c/0x80 [ 3290.970416] #6: ffffffff8280fca8 (dpm_list_mtx){+.+.}-{3:3}, at: dpm_resume+0x12e/0x3e0 [ 3290.970428] stack backtrace: [ 3290.970431] CPU: 3 PID: 4553 Comm: systemd-sleep Tainted: G S 5.15.0+ #2420 [ 3290.970438] Hardware name: Dell Inc. XPS 13 9380/0RYJWW, BIOS 1.5.0 06/03/2019 [ 3290.970441] Call Trace: [ 3290.970446] dump_stack_lvl+0x44/0x57 [ 3290.970454] check_noncircular+0x105/0x120 [ 3290.970468] ? __lock_acquire+0x15cb/0x1b50 [ 3290.970474] __lock_acquire+0x15cb/0x1b50 [ 3290.970487] lock_acquire+0x26c/0x300 [ 3290.970493] ? flush_workqueue+0x87/0x4a0 [ 3290.970503] ? __raw_spin_lock_init+0x3b/0x60 [ 3290.970510] ? lockdep_init_map_type+0x58/0x240 [ 3290.970519] flush_workqueue+0xae/0x4a0 [ 3290.970526] ? flush_workqueue+0x87/0x4a0 [ 3290.970544] ? drain_workqueue+0xa1/0x130 [ 3290.970552] drain_workqueue+0xa1/0x130 [ 3290.970561] destroy_workqueue+0x34/0x1f0 [ 3290.970572] hci_release_dev+0x49/0x180 [bluetooth] [ 3290.970624] bt_host_release+0x1d/0x30 [bluetooth] [ 3290.970687] device_release+0x33/0x90 [ 3290.970695] kobject_release+0x63/0x160 [ 3290.970705] dpm_resume+0x164/0x3e0 [ 3290.970710] ? dpm_resume_early+0x251/0x3b0 [ 3290.970718] dpm_resume_end+0xd/0x20 [ 3290.970723] suspend_devices_and_enter+0x1a4/0xba0 [ 3290.970737] pm_suspend+0x26b/0x310 [ 3290.970746] state_store+0x42/0x90 [ 3290.970755] kernfs_fop_write_iter+0x135/0x1b0 [ 3290.970764] new_sync_write+0x125/0x1c0 [ 3290.970777] vfs_write+0x360/0x3c0 [ 3290.970785] ksys_write+0xa7/0xe0 [ 3290.970794] do_syscall_64+0x3a/0x80 [ 3290.970803] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3290.970811] RIP: 0033:0x7f41b1328164 [ 3290.970819] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 80 00 00 00 00 8b 05 4a d2 2c 00 48 63 ff 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 f3 c3 66 90 55 53 48 89 d5 48 89 f3 48 83 [ 3290.970824] RSP: 002b:00007ffe6ae21b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 3290.970831] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f41b1328164 [ 3290.970836] RDX: 0000000000000004 RSI: 000055965e651070 RDI: 0000000000000004 [ 3290.970839] RBP: 000055965e651070 R08: 000055965e64f390 R09: 00007f41b1e3d1c0 [ 3290.970843] R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000004 [ 3290.970846] R13: 0000000000000001 R14: 000055965e64f2b0 R15: 0000000000000004 Cc: All applicable Signed-off-by: Rafael J. Wysocki

PM: sleep: Fix runtime PM based cpuidle support

2021-11-04T18:45:38Z

In the cpuidle-psci case, runtime PM in combination with the generic PM domain (genpd), may be used when entering/exiting a shared idlestate. More precisely, genpd relies on runtime PM to be enabled for the attached device (in this case it belongs to a CPU), to properly manage the reference counting of its PM domain. This works fine most of the time, but during system suspend in dpm_suspend_late(), the PM core disables runtime PM for all devices. Beyond this point, calls to pm_runtime_get_sync() to runtime resume a device may fail and therefore it could also mess up the reference counting in genpd. To fix this problem, let's call wake_up_all_idle_cpus() in dpm_suspend_late(), prior to disabling runtime PM. In this way a device that belongs to a CPU, becomes runtime resumed through cpuidle-psci and stays like that, because the runtime PM usage count has been bumped in device_prepare(). Diagnosed-by: Maulik Shah Suggested-by: Rafael J. Wysocki Signed-off-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM: sleep: Pause cpuidle later and resume it earlier during system transitions

2021-10-26T13:52:07Z

Commit 8651f97bd951 ("PM / cpuidle: System resume hang fix with cpuidle") that introduced cpuidle pausing during system suspend did that to work around a platform firmware issue causing systems to hang during resume if CPUs were allowed to enter idle states in the system suspend and resume code paths. However, pausing cpuidle before the last phase of suspending devices is the source of an otherwise arbitrary difference between the suspend-to-idle path and other system suspend variants, so it is cleaner to do that later, before taking secondary CPUs offline (it is still safer to take secondary CPUs offline with cpuidle paused, though). Modify the code accordingly, but in order to avoid code duplication, introduce new wrapper functions, pm_sleep_disable_secondary_cpus() and pm_sleep_enable_secondary_cpus(), to combine cpuidle_pause() and cpuidle_resume(), respectively, with the handling of secondary CPUs during system-wide transitions to sleep states. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Tested-by: Ulf Hansson

PM: suspend: Do not pause cpuidle in the suspend-to-idle path

2021-10-26T13:52:07Z

It is pointless to pause cpuidle in the suspend-to-idle path, because it is going to be resumed in the same path later and pausing it does not serve any particular purpose in that case. Rework the code to avoid doing that. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Tested-by: Ulf Hansson

PM: sleep: Do not let "syscore" devices runtime-suspend during system transitions

2021-10-22T16:09:58Z

There is no reason to allow "syscore" devices to runtime-suspend during system-wide PM transitions, because they are subject to the same possible failure modes as any other devices in that respect. Accordingly, change device_prepare() and device_complete() to call pm_runtime_get_noresume() and pm_runtime_put(), respectively, for "syscore" devices too. Fixes: 057d51a1268f ("Merge branch 'pm-sleep'") Signed-off-by: Rafael J. Wysocki Cc: 3.10+ # 3.10+ Reviewed-by: Ulf Hansson

PM: sleep: core: Avoid setting power.must_resume to false

2021-09-07T19:18:34Z

There are variables(power.may_skip_resume and dev->power.must_resume) and DPM_FLAG_MAY_SKIP_RESUME flags to control the resume of devices after a system wide suspend transition. Setting the DPM_FLAG_MAY_SKIP_RESUME flag means that the driver allows its "noirq" and "early" resume callbacks to be skipped if the device can be left in suspend after a system-wide transition into the working state. PM core determines that the driver's "noirq" and "early" resume callbacks should be skipped or not with dev_pm_skip_resume() function by checking power.may_skip_resume variable. power.must_resume variable is getting set to false in __device_suspend() function without checking device's DPM_FLAG_MAY_SKIP_RESUME settings. In problematic scenario, where all the devices in the suspend_late stage are successful and some device can fail to suspend in suspend_noirq phase. So some devices successfully suspended in suspend_late stage are not getting chance to execute __device_suspend_noirq() to set dev->power.must_resume variable to true and not getting resumed in early_resume phase. Add a check for device's DPM_FLAG_MAY_SKIP_RESUME flag before setting power.must_resume variable in __device_suspend function. Fixes: 6e176bf8d461 ("PM: sleep: core: Do not skip callbacks in the resume phase") Signed-off-by: Prasad Sodagudi Signed-off-by: Rafael J. Wysocki