From 1d531c14d2ed4b24472a4d773f00ed6d1cd34ee7 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Sun, 13 Dec 2009 20:28:30 +0100 Subject: [PATCH 1/4] PM: allow for usage_count > 0 in pm_runtime_get() This patch (as1308c) fixes __pm_runtime_get(). Currently the routine will resume a device if the prior usage count was 0. But this isn't right; thanks to pm_runtime_get_noresume() the usage count can be positive even while the device is suspended. Signed-off-by: Alan Stern Signed-off-by: Rafael J. Wysocki --- drivers/base/power/runtime.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 5a01ecef4af..40d7720a4b2 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -701,15 +701,15 @@ EXPORT_SYMBOL_GPL(pm_request_resume); * @dev: Device to handle. * @sync: If set and the device is suspended, resume it synchronously. * - * Increment the usage count of the device and if it was zero previously, - * resume it or submit a resume request for it, depending on the value of @sync. + * Increment the usage count of the device and resume it or submit a resume + * request for it, depending on the value of @sync. */ int __pm_runtime_get(struct device *dev, bool sync) { - int retval = 1; + int retval; - if (atomic_add_return(1, &dev->power.usage_count) == 1) - retval = sync ? pm_runtime_resume(dev) : pm_request_resume(dev); + atomic_inc(&dev->power.usage_count); + retval = sync ? pm_runtime_resume(dev) : pm_request_resume(dev); return retval; } From f2511774863487e61b56a97da07ebf8dd61d7836 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Sun, 13 Dec 2009 20:29:01 +0100 Subject: [PATCH 2/4] PM: Add initcall_debug style timing for suspend/resume In order to diagnose overall suspend/resume times, we need basic instrumentation to break down the total time into per device timing, similar to initcall_debug. This patch adds the basic timing instrumentation, needed for a scritps/bootgraph.pl equivalent or humans. The bootgraph.pl program is still a work in progress, but is far enough along to know that this patch is sufficient. Signed-off-by: Arjan van de Ven Signed-off-by: Rafael J. Wysocki --- drivers/base/power/main.c | 31 +++++++++++++++++++++++++++++++ include/linux/init.h | 2 ++ 2 files changed, 33 insertions(+) diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 8aa2443182d..30f0ceebd36 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -25,6 +25,7 @@ #include #include #include +#include #include "../base.h" #include "power.h" @@ -172,6 +173,13 @@ static int pm_op(struct device *dev, pm_message_t state) { int error = 0; + ktime_t calltime, delta, rettime; + + if (initcall_debug) { + pr_info("calling %s+ @ %i\n", + dev_name(dev), task_pid_nr(current)); + calltime = ktime_get(); + } switch (state.event) { #ifdef CONFIG_SUSPEND @@ -219,6 +227,14 @@ static int pm_op(struct device *dev, default: error = -EINVAL; } + + if (initcall_debug) { + rettime = ktime_get(); + delta = ktime_sub(rettime, calltime); + pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev), + error, (unsigned long long)ktime_to_ns(delta) >> 10); + } + return error; } @@ -236,6 +252,13 @@ static int pm_noirq_op(struct device *dev, pm_message_t state) { int error = 0; + ktime_t calltime, delta, rettime; + + if (initcall_debug) { + pr_info("calling %s_i+ @ %i\n", + dev_name(dev), task_pid_nr(current)); + calltime = ktime_get(); + } switch (state.event) { #ifdef CONFIG_SUSPEND @@ -283,6 +306,14 @@ static int pm_noirq_op(struct device *dev, default: error = -EINVAL; } + + if (initcall_debug) { + rettime = ktime_get(); + delta = ktime_sub(rettime, calltime); + printk("initcall %s_i+ returned %d after %Ld usecs\n", dev_name(dev), + error, (unsigned long long)ktime_to_ns(delta) >> 10); + } + return error; } diff --git a/include/linux/init.h b/include/linux/init.h index ff8bde520d0..ab1d31f9352 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -149,6 +149,8 @@ void prepare_namespace(void); extern void (*late_time_init)(void); +extern int initcall_debug; + #endif #ifndef MODULE From 33c3374031facf7599c30a1548dfa4c83da87da3 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sun, 13 Dec 2009 20:31:12 +0100 Subject: [PATCH 3/4] PM: Remove unnecessary goto from device_resume_noirq() In device_resume_noirq() there is the 'End' label and the associated goto statement that aren't strictly necessary, so rework the code to get rid of them. Also modify device_suspend_noirq() so that it looks completely analogous to device_resume_noirq(). Signed-off-by: Rafael J. Wysocki --- drivers/base/power/main.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 30f0ceebd36..df04cb4a361 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -372,14 +372,11 @@ static int device_resume_noirq(struct device *dev, pm_message_t state) TRACE_DEVICE(dev); TRACE_RESUME(0); - if (!dev->bus) - goto End; - - if (dev->bus->pm) { + if (dev->bus && dev->bus->pm) { pm_dev_dbg(dev, state, "EARLY "); error = pm_noirq_op(dev, dev->bus->pm, state); } - End: + TRACE_RESUME(error); return error; } @@ -615,10 +612,7 @@ static int device_suspend_noirq(struct device *dev, pm_message_t state) { int error = 0; - if (!dev->bus) - return 0; - - if (dev->bus->pm) { + if (dev->bus && dev->bus->pm) { pm_dev_dbg(dev, state, "LATE "); error = pm_noirq_op(dev, dev->bus->pm, state); } From d8bed5a4f343d1826153ecf8e7932126c757a21d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sun, 13 Dec 2009 20:48:54 +0100 Subject: [PATCH 4/4] PM: rwsem.h need not be included into main.c It is not necessary to include into drivers/base/power/main.c, so don't do that. Signed-off-by: Rafael J. Wysocki --- drivers/base/power/main.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index df04cb4a361..1a216c114a0 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -23,7 +23,6 @@ #include #include #include -#include #include #include