From bb3632c6101b2fad07e6246721466b984b1e0e9d Mon Sep 17 00:00:00 2001 From: Todd E Brandt Date: Fri, 6 Jun 2014 05:40:17 -0700 Subject: PM / sleep: trace events for suspend/resume Adds trace events that give finer resolution into suspend/resume. These events are graphed in the timelines generated by the analyze_suspend.py script. They represent large areas of time consumed that are typical to suspend and resume. The event is triggered by calling the function "trace_suspend_resume" with three arguments: a string (the name of the event to be displayed in the timeline), an integer (case specific number, such as the power state or cpu number), and a boolean (where true is used to denote the start of the timeline event, and false to denote the end). The suspend_resume trace event reproduces the data that the machine_suspend trace event did, so the latter has been removed. Signed-off-by: Todd Brandt Acked-by: Steven Rostedt Signed-off-by: Rafael J. Wysocki --- kernel/power/process.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel/power/process.c') diff --git a/kernel/power/process.c b/kernel/power/process.c index 06ec8869dbf..0ca8d83e236 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -17,6 +17,7 @@ #include #include #include +#include /* * Timeout for stopping processes @@ -175,6 +176,7 @@ void thaw_processes(void) struct task_struct *g, *p; struct task_struct *curr = current; + trace_suspend_resume(TPS("thaw_processes"), 0, true); if (pm_freezing) atomic_dec(&system_freezing_cnt); pm_freezing = false; @@ -201,6 +203,7 @@ void thaw_processes(void) schedule(); printk("done.\n"); + trace_suspend_resume(TPS("thaw_processes"), 0, false); } void thaw_kernel_threads(void) -- cgit v1.2.3-70-g09d2 From 4320f6b1d9db4ca912c5eb6ecb328b2e090e1586 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 15 Jul 2014 08:51:27 +0200 Subject: PM / sleep: Fix request_firmware() error at resume The commit [247bc037: PM / Sleep: Mitigate race between the freezer and request_firmware()] introduced the finer state control, but it also leads to a new bug; for example, a bug report regarding the firmware loading of intel BT device at suspend/resume: https://bugzilla.novell.com/show_bug.cgi?id=873790 The root cause seems to be a small window between the process resume and the clear of usermodehelper lock. The request_firmware() function checks the UMH lock and gives up when it's in UMH_DISABLE state. This is for avoiding the invalid f/w loading during suspend/resume phase. The problem is, however, that usermodehelper_enable() is called at the end of thaw_processes(). Thus, a thawed process in between can kick off the f/w loader code path (in this case, via btusb_setup_intel()) even before the call of usermodehelper_enable(). Then usermodehelper_read_trylock() returns an error and request_firmware() spews WARN_ON() in the end. This oneliner patch fixes the issue just by setting to UMH_FREEZING state again before restarting tasks, so that the call of request_firmware() will be blocked until the end of this function instead of returning an error. Fixes: 247bc0374254 (PM / Sleep: Mitigate race between the freezer and request_firmware()) Link: https://bugzilla.novell.com/show_bug.cgi?id=873790 Cc: 3.4+ # 3.4+ Signed-off-by: Takashi Iwai Signed-off-by: Rafael J. Wysocki --- kernel/power/process.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/power/process.c') diff --git a/kernel/power/process.c b/kernel/power/process.c index 0ca8d83e236..4ee194eb524 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -186,6 +186,7 @@ void thaw_processes(void) printk("Restarting tasks ... "); + __usermodehelper_set_disable_depth(UMH_FREEZING); thaw_workqueues(); read_lock(&tasklist_lock); -- cgit v1.2.3-70-g09d2