From cf579dfb82550e34de7ccf3ef090d8b834ccd3a9 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sun, 29 Jan 2012 20:38:29 +0100 Subject: PM / Sleep: Introduce "late suspend" and "early resume" of devices The current device suspend/resume phases during system-wide power transitions appear to be insufficient for some platforms that want to use the same callback routines for saving device states and related operations during runtime suspend/resume as well as during system suspend/resume. In principle, they could point their .suspend_noirq() and .resume_noirq() to the same callback routines as their .runtime_suspend() and .runtime_resume(), respectively, but at least some of them require device interrupts to be enabled while the code in those routines is running. It also makes sense to have device suspend-resume callbacks that will be executed with runtime PM disabled and with device interrupts enabled in case someone needs to run some special code in that context during system-wide power transitions. Apart from this, .suspend_noirq() and .resume_noirq() were introduced as a workaround for drivers using shared interrupts and failing to prevent their interrupt handlers from accessing suspended hardware. It appears to be better not to use them for other porposes, or we may have to deal with some serious confusion (which seems to be happening already). For the above reasons, introduce new device suspend/resume phases, "late suspend" and "early resume" (and analogously for hibernation) whose callback will be executed with runtime PM disabled and with device interrupts enabled and whose callback pointers generally may point to runtime suspend/resume routines. Signed-off-by: Rafael J. Wysocki Reviewed-by: Mark Brown Reviewed-by: Kevin Hilman --- kernel/power/hibernate.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) (limited to 'kernel/power/hibernate.c') diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 6d6d2887033..a5d4cf0aa03 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -245,8 +245,8 @@ void swsusp_show_speed(struct timeval *start, struct timeval *stop, * create_image - Create a hibernation image. * @platform_mode: Whether or not to use the platform driver. * - * Execute device drivers' .freeze_noirq() callbacks, create a hibernation image - * and execute the drivers' .thaw_noirq() callbacks. + * Execute device drivers' "late" and "noirq" freeze callbacks, create a + * hibernation image and run the drivers' "noirq" and "early" thaw callbacks. * * Control reappears in this routine after the subsequent restore. */ @@ -254,7 +254,7 @@ static int create_image(int platform_mode) { int error; - error = dpm_suspend_noirq(PMSG_FREEZE); + error = dpm_suspend_end(PMSG_FREEZE); if (error) { printk(KERN_ERR "PM: Some devices failed to power down, " "aborting hibernation\n"); @@ -306,7 +306,7 @@ static int create_image(int platform_mode) Platform_finish: platform_finish(platform_mode); - dpm_resume_noirq(in_suspend ? + dpm_resume_start(in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE); return error; @@ -394,16 +394,16 @@ int hibernation_snapshot(int platform_mode) * resume_target_kernel - Restore system state from a hibernation image. * @platform_mode: Whether or not to use the platform driver. * - * Execute device drivers' .freeze_noirq() callbacks, restore the contents of - * highmem that have not been restored yet from the image and run the low-level - * code that will restore the remaining contents of memory and switch to the - * just restored target kernel. + * Execute device drivers' "noirq" and "late" freeze callbacks, restore the + * contents of highmem that have not been restored yet from the image and run + * the low-level code that will restore the remaining contents of memory and + * switch to the just restored target kernel. */ static int resume_target_kernel(bool platform_mode) { int error; - error = dpm_suspend_noirq(PMSG_QUIESCE); + error = dpm_suspend_end(PMSG_QUIESCE); if (error) { printk(KERN_ERR "PM: Some devices failed to power down, " "aborting resume\n"); @@ -460,7 +460,7 @@ static int resume_target_kernel(bool platform_mode) Cleanup: platform_restore_cleanup(platform_mode); - dpm_resume_noirq(PMSG_RECOVER); + dpm_resume_start(PMSG_RECOVER); return error; } @@ -518,7 +518,7 @@ int hibernation_platform_enter(void) goto Resume_devices; } - error = dpm_suspend_noirq(PMSG_HIBERNATE); + error = dpm_suspend_end(PMSG_HIBERNATE); if (error) goto Resume_devices; @@ -549,7 +549,7 @@ int hibernation_platform_enter(void) Platform_finish: hibernation_ops->finish(); - dpm_resume_noirq(PMSG_RESTORE); + dpm_resume_start(PMSG_RESTORE); Resume_devices: entering_platform_hibernation = false; -- cgit v1.2.3-70-g09d2 From 51d6ff7acd920379f54d0be4dbe844a46178a65f Mon Sep 17 00:00:00 2001 From: "Srivatsa S. Bhat" Date: Sat, 4 Feb 2012 22:26:38 +0100 Subject: PM / Hibernate: Thaw kernel threads in hibernation_snapshot() in error/test path In the hibernation call path, the kernel threads are frozen inside hibernation_snapshot(). If we happen to encounter an error further down the road or if we are exiting early due to a successful freezer test, then thaw kernel threads before returning to the caller. Signed-off-by: Srivatsa S. Bhat Acked-by: Tejun Heo Signed-off-by: Rafael J. Wysocki --- kernel/power/hibernate.c | 6 ++++-- kernel/power/user.c | 8 ++------ 2 files changed, 6 insertions(+), 8 deletions(-) (limited to 'kernel/power/hibernate.c') diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index a5d4cf0aa03..c6dee739080 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -343,13 +343,13 @@ int hibernation_snapshot(int platform_mode) * successful freezer test. */ freezer_test_done = true; - goto Cleanup; + goto Thaw; } error = dpm_prepare(PMSG_FREEZE); if (error) { dpm_complete(PMSG_RECOVER); - goto Cleanup; + goto Thaw; } suspend_console(); @@ -385,6 +385,8 @@ int hibernation_snapshot(int platform_mode) platform_end(platform_mode); return error; + Thaw: + thaw_kernel_threads(); Cleanup: swsusp_free(); goto Close; diff --git a/kernel/power/user.c b/kernel/power/user.c index 3e100075b13..7bee91f9af5 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -249,16 +249,12 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, } pm_restore_gfp_mask(); error = hibernation_snapshot(data->platform_support); - if (error) { - thaw_kernel_threads(); - } else { + if (!error) { error = put_user(in_suspend, (int __user *)arg); if (!error && !freezer_test_done) data->ready = 1; - if (freezer_test_done) { + if (freezer_test_done) freezer_test_done = false; - thaw_kernel_threads(); - } } break; -- cgit v1.2.3-70-g09d2 From a556d5b58345ccf51826b9ceac078072f830738b Mon Sep 17 00:00:00 2001 From: "Srivatsa S. Bhat" Date: Sat, 4 Feb 2012 23:39:56 +0100 Subject: PM / Hibernate: Refactor and simplify freezer_test_done The code related to 'freezer_test_done' is needlessly convoluted. Refactor the code and simplify the implementation. Signed-off-by: Srivatsa S. Bhat Signed-off-by: Rafael J. Wysocki --- kernel/power/hibernate.c | 10 +++++----- kernel/power/user.c | 6 ++---- 2 files changed, 7 insertions(+), 9 deletions(-) (limited to 'kernel/power/hibernate.c') diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index c6dee739080..72baaf011fb 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -629,12 +629,8 @@ int hibernate(void) goto Finish; error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM); - if (error) - goto Thaw; - if (freezer_test_done) { - freezer_test_done = false; + if (error || freezer_test_done) goto Thaw; - } if (in_suspend) { unsigned int flags = 0; @@ -659,6 +655,10 @@ int hibernate(void) Thaw: thaw_processes(); + + /* Don't bother checking whether freezer_test_done is true */ + freezer_test_done = false; + Finish: free_basic_memory_bitmaps(); usermodehelper_enable(); diff --git a/kernel/power/user.c b/kernel/power/user.c index 7bee91f9af5..33c4329205a 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -251,10 +251,8 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, error = hibernation_snapshot(data->platform_support); if (!error) { error = put_user(in_suspend, (int __user *)arg); - if (!error && !freezer_test_done) - data->ready = 1; - if (freezer_test_done) - freezer_test_done = false; + data->ready = !freezer_test_done && !error; + freezer_test_done = false; } break; -- cgit v1.2.3-70-g09d2 From 05b4877f6a4f1ba4952d1222213d262bf8c132b7 Mon Sep 17 00:00:00 2001 From: "Srivatsa S. Bhat" Date: Fri, 17 Feb 2012 23:39:51 +0100 Subject: PM / Hibernate: Enable usermodehelpers in hibernate() error path If create_basic_memory_bitmaps() fails, usermodehelpers are not re-enabled before returning. Fix this. And while at it, reword the goto labels so that they look more meaningful. Signed-off-by: Srivatsa S. Bhat Cc: stable@vger.kernel.org Signed-off-by: Rafael J. Wysocki --- kernel/power/hibernate.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'kernel/power/hibernate.c') diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 72baaf011fb..0a186cfde78 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -618,7 +618,7 @@ int hibernate(void) /* Allocate memory management structures */ error = create_basic_memory_bitmaps(); if (error) - goto Exit; + goto Enable_umh; printk(KERN_INFO "PM: Syncing filesystems ... "); sys_sync(); @@ -626,7 +626,7 @@ int hibernate(void) error = freeze_processes(); if (error) - goto Finish; + goto Free_bitmaps; error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM); if (error || freezer_test_done) @@ -659,8 +659,9 @@ int hibernate(void) /* Don't bother checking whether freezer_test_done is true */ freezer_test_done = false; - Finish: + Free_bitmaps: free_basic_memory_bitmaps(); + Enable_umh: usermodehelper_enable(); Exit: pm_notifier_call_chain(PM_POST_HIBERNATION); -- cgit v1.2.3-70-g09d2 From 7b5179ac14dbad945647ac9e76bbbf14ed9e0dbe Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 28 Mar 2012 23:30:14 +0200 Subject: PM / Hibernate: Disable usermode helpers right before freezing tasks 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 --- kernel/power/hibernate.c | 23 ++++++++++------------- 1 file changed, 10 insertions(+), 13 deletions(-) (limited to 'kernel/power/hibernate.c') diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 0a186cfde78..639ff6e4ae9 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -611,19 +611,19 @@ int hibernate(void) if (error) goto Exit; - error = usermodehelper_disable(); - if (error) - goto Exit; - /* Allocate memory management structures */ error = create_basic_memory_bitmaps(); if (error) - goto Enable_umh; + goto Exit; printk(KERN_INFO "PM: Syncing filesystems ... "); sys_sync(); printk("done.\n"); + error = usermodehelper_disable(); + if (error) + goto Exit; + error = freeze_processes(); if (error) goto Free_bitmaps; @@ -660,9 +660,8 @@ int hibernate(void) freezer_test_done = false; Free_bitmaps: - free_basic_memory_bitmaps(); - Enable_umh: usermodehelper_enable(); + free_basic_memory_bitmaps(); Exit: pm_notifier_call_chain(PM_POST_HIBERNATION); pm_restore_console(); @@ -777,15 +776,13 @@ static int software_resume(void) if (error) goto close_finish; - error = usermodehelper_disable(); + error = create_basic_memory_bitmaps(); if (error) goto close_finish; - error = create_basic_memory_bitmaps(); - if (error) { - usermodehelper_enable(); + error = usermodehelper_disable(); + if (error) goto close_finish; - } pr_debug("PM: Preparing processes for restore.\n"); error = freeze_processes(); @@ -805,8 +802,8 @@ static int software_resume(void) swsusp_free(); thaw_processes(); Done: - free_basic_memory_bitmaps(); usermodehelper_enable(); + free_basic_memory_bitmaps(); Finish: pm_notifier_call_chain(PM_POST_RESTORE); pm_restore_console(); -- cgit v1.2.3-70-g09d2 From 1e73203cd1157a03facc41ffb54050f5b28e55bd Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 28 Mar 2012 23:30:21 +0200 Subject: PM / Sleep: Move disabling of usermode helpers to the freezer 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 --- kernel/power/hibernate.c | 11 ----------- kernel/power/process.c | 7 +++++++ kernel/power/suspend.c | 7 ------- kernel/power/user.c | 10 +--------- 4 files changed, 8 insertions(+), 27 deletions(-) (limited to 'kernel/power/hibernate.c') diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 639ff6e4ae9..e09dfbfeece 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -16,7 +16,6 @@ #include #include #include -#include #include #include #include @@ -620,10 +619,6 @@ int hibernate(void) sys_sync(); printk("done.\n"); - error = usermodehelper_disable(); - if (error) - goto Exit; - error = freeze_processes(); if (error) goto Free_bitmaps; @@ -660,7 +655,6 @@ int hibernate(void) freezer_test_done = false; Free_bitmaps: - usermodehelper_enable(); free_basic_memory_bitmaps(); Exit: pm_notifier_call_chain(PM_POST_HIBERNATION); @@ -780,10 +774,6 @@ static int software_resume(void) if (error) goto close_finish; - error = usermodehelper_disable(); - if (error) - goto close_finish; - pr_debug("PM: Preparing processes for restore.\n"); error = freeze_processes(); if (error) { @@ -802,7 +792,6 @@ static int software_resume(void) swsusp_free(); thaw_processes(); Done: - usermodehelper_enable(); free_basic_memory_bitmaps(); Finish: pm_notifier_call_chain(PM_POST_RESTORE); diff --git a/kernel/power/process.c b/kernel/power/process.c index 0d2aeb22610..56eaac7e88a 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -16,6 +16,7 @@ #include #include #include +#include /* * Timeout for stopping processes @@ -122,6 +123,10 @@ int freeze_processes(void) { int error; + error = usermodehelper_disable(); + if (error) + return error; + if (!pm_freezing) atomic_inc(&system_freezing_cnt); @@ -187,6 +192,8 @@ void thaw_processes(void) } while_each_thread(g, p); read_unlock(&tasklist_lock); + usermodehelper_enable(); + schedule(); printk("done.\n"); } diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 88e5c967370..396d262b8fd 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -12,7 +12,6 @@ #include #include #include -#include #include #include #include @@ -102,17 +101,12 @@ static int suspend_prepare(void) if (error) goto Finish; - error = usermodehelper_disable(); - if (error) - goto Finish; - error = suspend_freeze_processes(); if (!error) return 0; suspend_stats.failed_freeze++; dpm_save_failed_step(SUSPEND_FREEZE); - usermodehelper_enable(); Finish: pm_notifier_call_chain(PM_POST_SUSPEND); pm_restore_console(); @@ -259,7 +253,6 @@ int suspend_devices_and_enter(suspend_state_t state) static void suspend_finish(void) { suspend_thaw_processes(); - usermodehelper_enable(); pm_notifier_call_chain(PM_POST_SUSPEND); pm_restore_console(); } diff --git a/kernel/power/user.c b/kernel/power/user.c index 33c4329205a..91b0fd021a9 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -12,7 +12,6 @@ #include #include #include -#include #include #include #include @@ -222,14 +221,8 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, sys_sync(); printk("done.\n"); - error = usermodehelper_disable(); - if (error) - break; - error = freeze_processes(); - if (error) - usermodehelper_enable(); - else + if (!error) data->frozen = 1; break; @@ -238,7 +231,6 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, break; pm_restore_gfp_mask(); thaw_processes(); - usermodehelper_enable(); data->frozen = 0; break; -- cgit v1.2.3-70-g09d2