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Hi, The following series of patches removes some unused and unnecessary features from the suspend and resume core code. Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth -
From: Rafael J. Wysocki <rjw@sisk.pl>
The pm_parent member of struct dev_pm_info (defined in include/linux/pm.h) is
only used to check if the device's parent is in the right state while the
device is being suspended or resumed. However, this can be done just as well
with the help of the parent pointer in struct device, so pm_parent can be
removed along with some code that handles it.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
---
drivers/base/power/main.c | 30 ++++--------------------------
drivers/base/power/resume.c | 7 +++----
drivers/base/power/suspend.c | 7 +++----
include/linux/pm.h | 3 ---
4 files changed, 10 insertions(+), 37 deletions(-)
Index: linux-2.6.22-rc4-mm2/drivers/base/power/main.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/drivers/base/power/main.c
+++ linux-2.6.22-rc4-mm2/drivers/base/power/main.c
@@ -33,28 +33,7 @@ DEFINE_MUTEX(dpm_list_mtx);
int (*platform_enable_wakeup)(struct device *dev, int is_on);
-
-/**
- * device_pm_set_parent - Specify power dependency.
- * @dev: Device who needs power.
- * @parent: Device that supplies power.
- *
- * This function is used to manually describe a power-dependency
- * relationship. It may be used to specify a transversal relationship
- * (where the power supplier is not the physical (or electrical)
- * ancestor of a specific device.
- * The effect of this is that the supplier will not be powered down
- * before the power dependent.
- */
-
-void device_pm_set_parent(struct device * dev, struct device * parent)
-{
- put_device(dev->power.pm_parent);
- dev->power.pm_parent = get_device(parent);
-}
-EXPORT_SYMBOL_GPL(device_pm_set_parent);
-
-int device_pm_add(struct device * dev)
+int device_pm_add(struct device *dev)
{
int error;
@@ -63,21 +42,20 @@ int device_pm_add(struct device * dev)
kobject_name(&dev->kobj));
...From: Rafael J. Wysocki <rjw@sisk.pl>
Reduce code duplication in drivers/base/suspend.c by introducing a separate
function for printing diagnostic messages.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
---
drivers/base/power/suspend.c | 49 +++++++++++++++----------------------------
1 file changed, 18 insertions(+), 31 deletions(-)
Index: linux-2.6.22-rc4-mm2/drivers/base/power/suspend.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/drivers/base/power/suspend.c
+++ linux-2.6.22-rc4-mm2/drivers/base/power/suspend.c
@@ -40,6 +40,14 @@ static inline char *suspend_verb(u32 eve
}
+static void
+suspend_device_dbg(struct device * dev, pm_message_t state, char *info)
+{
+ dev_dbg(dev, "%s%s%s\n", info, suspend_verb(state.event),
+ ((state.event == PM_EVENT_SUSPEND) && device_may_wakeup(dev)) ?
+ ", may wakeup" : "");
+}
+
/**
* suspend_device - Save state of one device.
* @dev: Device.
@@ -66,37 +74,21 @@ int suspend_device(struct device * dev,
dev->power.prev_state = dev->power.power_state;
if (dev->class && dev->class->suspend && !dev->power.power_state.event) {
- dev_dbg(dev, "class %s%s\n",
- suspend_verb(state.event),
- ((state.event == PM_EVENT_SUSPEND)
- && device_may_wakeup(dev))
- ? ", may wakeup"
- : ""
- );
+ suspend_device_dbg(dev, state, "class ");
error = dev->class->suspend(dev, state);
suspend_report_result(dev->class->suspend, error);
}
- if (!error && dev->type && dev->type->suspend && !dev->power.power_state.event) {
- dev_dbg(dev, "%s%s\n",
- suspend_verb(state.event),
- ((state.event == PM_EVENT_SUSPEND)
- && device_may_wakeup(dev))
- ? ", may wakeup"
- : ""
- );
+ if (!error && dev->type && dev->type->suspend
+ && !dev->power.power_state.event) {
+ suspend_device_dbg(dev, state, "type ");
error = dev->type->suspend(dev, state);
...From: Rafael J. Wysocki <rjw@sisk.pl>
The suspend and resume support in struct device_type (include/linux/device.h)
is not used anywhere. It is also undocumented, so it can be removed.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
drivers/base/power/resume.c | 5 -----
drivers/base/power/suspend.c | 7 -------
include/linux/device.h | 2 --
3 files changed, 14 deletions(-)
Index: linux-2.6.22-rc4-mm2/drivers/base/power/resume.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/drivers/base/power/resume.c
+++ linux-2.6.22-rc4-mm2/drivers/base/power/resume.c
@@ -41,11 +41,6 @@ int resume_device(struct device * dev)
error = dev->bus->resume(dev);
}
- if (!error && dev->type && dev->type->resume) {
- dev_dbg(dev,"resuming\n");
- error = dev->type->resume(dev);
- }
-
if (!error && dev->class && dev->class->resume) {
dev_dbg(dev,"class resume\n");
error = dev->class->resume(dev);
Index: linux-2.6.22-rc4-mm2/drivers/base/power/suspend.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/drivers/base/power/suspend.c
+++ linux-2.6.22-rc4-mm2/drivers/base/power/suspend.c
@@ -79,13 +79,6 @@ int suspend_device(struct device * dev,
suspend_report_result(dev->class->suspend, error);
}
- if (!error && dev->type && dev->type->suspend
- && !dev->power.power_state.event) {
- suspend_device_dbg(dev, state, "type ");
- error = dev->type->suspend(dev, state);
- suspend_report_result(dev->type->suspend, error);
- }
-
if (!error && dev->bus && dev->bus->suspend
&& !dev->power.power_state.event) {
suspend_device_dbg(dev, state, "");
Index: linux-2.6.22-rc4-mm2/include/linux/device.h
===================================================================
--- linux-2.6.22-rc4-mm2.orig/include/linux/device.h
+++ linux-2.6.22-rc4-mm2/include/linux/device.h
@@ -340,8 +340,6 @@ struct device_type {
int (*uevent)(struct device ...Dmitry, you added this recently, is this used in any code you plan to merge soon? Thanks, Kay -
Yes, I will need it to implement input device resume (mainly to restore LED state and repeat rate for keyboards). -- Dmitry -
Would that be a big problem to reintroduce it along with the user? Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth -
Yes because that part is in Greg's domain so I am trying to set infrastructure up before I can commit my patches into my tree so that Andrew can safely pull from me into -mm. Greg normally adds such stuff during merge window so that means if we remove it now we'd need ~2 releases to get it and the user back in. -- Dmitry -
Yes, don't worry, I'm not going to remove this as I know you rely on it. Sorry for the delay in getting to these patches, I'm in meetings down in CA for the rest of the week... thanks, greg k-h -
Hm, in that case I'd have to rework the patches 5-7. Perhaps I should resend No big deal. :-) Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth -
You do? Conflicts are that bad? Let me try and apply them and let you know what I've accepted in my tree... thanks, greg k-h -
Ok, yeah, can you rework those three patches and resend them? I took patches 1-3 already. thanks, greg k-h -
Thanks! Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth -
Hi, The next messages contain the remaining three patches from the previous series "PM: Remove unused and unnecessary features from suspend and resume core" that I have promised to resend. The patches apply to 2.6.22-rc4-mm2, which is particularly important for the first one, as it is on top of some recent USB changes that right now are mm-only. If there are any problems with that, please let me know. Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth -
From: Rafael J. Wysocki <rjw@sisk.pl>
The checks if the device's parent is in the right state done in
drivers/base/power/suspend.c and drivers/base/power/resume.c serve no particular
purpose, since if the parent is in a wrong power state, the device's suspend or
resume callbacks are supposed to return an error anyway. Moreover, they are
also useless from the sanity checking point of view, because they rely on the
code being checked to set dev->parent->power.power_state.event appropriately,
which need not happen if that code is buggy. For these reasons they can be
removed.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
---
drivers/base/power/resume.c | 7 -------
drivers/base/power/suspend.c | 7 -------
2 files changed, 14 deletions(-)
Index: linux-2.6.22-rc4/drivers/base/power/resume.c
===================================================================
--- linux-2.6.22-rc4.orig/drivers/base/power/resume.c 2007-06-16 01:08:13.000000000 +0200
+++ linux-2.6.22-rc4/drivers/base/power/resume.c 2007-06-16 01:12:53.000000000 +0200
@@ -29,13 +29,6 @@ int resume_device(struct device * dev)
down(&dev->sem);
- if (dev->parent && dev->parent->power.power_state.event) {
- dev_err(dev, "PM: resume from %d, parent %s still %d\n",
- dev->power.power_state.event,
- dev->parent->bus_id,
- dev->parent->power.power_state.event);
- }
-
if (dev->bus && dev->bus->resume) {
dev_dbg(dev,"resuming\n");
error = dev->bus->resume(dev);
Index: linux-2.6.22-rc4/drivers/base/power/suspend.c
===================================================================
--- linux-2.6.22-rc4.orig/drivers/base/power/suspend.c 2007-06-16 01:12:04.000000000 +0200
+++ linux-2.6.22-rc4/drivers/base/power/suspend.c 2007-06-16 01:12:53.000000000 +0200
@@ -63,13 +63,6 @@ int suspend_device(struct device * dev,
dev_dbg(dev, "PM: suspend %d-->%d\n",
dev->power.power_state.event, state.event);
}
- if (dev->parent && ...From: Rafael J. Wysocki <rjw@sisk.pl>
The prev_state member of struct dev_pm_info (defined in include/linux/pm.h) is
only used during a resume to check if the device's state before the suspend was
'off', in which case the device is not resumed. However, in such cases the
decision whether or not to resume the device should be made on the driver level
and the resume callbacks from the device's bus and class should be executed
anyway (the may be needed for some things other than just powering on the
device).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
drivers/base/power/resume.c | 3 +--
drivers/base/power/suspend.c | 2 --
drivers/usb/core/hub.c | 5 -----
drivers/usb/host/ohci-pci.c | 2 --
include/linux/pm.h | 1 -
5 files changed, 1 insertion(+), 12 deletions(-)
Index: linux-2.6.22-rc4-mm2/drivers/base/power/resume.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/drivers/base/power/resume.c
+++ linux-2.6.22-rc4-mm2/drivers/base/power/resume.c
@@ -88,8 +88,7 @@ void dpm_resume(void)
list_move_tail(entry, &dpm_active);
mutex_unlock(&dpm_list_mtx);
- if (!dev->power.prev_state.event)
- resume_device(dev);
+ resume_device(dev);
mutex_lock(&dpm_list_mtx);
put_device(dev);
}
Index: linux-2.6.22-rc4-mm2/drivers/base/power/suspend.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/drivers/base/power/suspend.c
+++ linux-2.6.22-rc4-mm2/drivers/base/power/suspend.c
@@ -71,8 +71,6 @@ int suspend_device(struct device * dev,
dev->parent->power.power_state.event);
}
- dev->power.prev_state = dev->power.power_state;
-
if (dev->class && dev->class->suspend && !dev->power.power_state.event) {
suspend_device_dbg(dev, state, "class ");
error = dev->class->suspend(dev, state);
Index: linux-2.6.22-rc4-mm2/drivers/usb/core/hub.c
===================================================================
--- ...Why wouldn't that use the class device suspend/resume mechanism? -
Because they are not class devices anymore. -- Dmitry -
Perhaps you mis-understood me: the class level device suspend/resume hooks don't rely on class_device. I observe that /sys/class/input still exists (2.6.22-rc4-git), so if all you mean is that it's no longer using class_device, that's good. One part of the reason to stop using class_device is specifically to let framework code (like input, network, or rtc) receive class level suspend/resume calls. ISTR the RTC framework was the first to do that, but there's some work afoot to teach the network stack to use that mechanism too. Or are you referring to some input patches which I've not yet seen, which cause /sys/class/input to vanish? - Dave -
Yes, I did misunderstood you. The reason I can't use class-wide resume support is that since we can't have class hierarchy we have mess of different objects dumped into single pool (input_dev, evdev. mousedev, joydev, tsdev all relate to /sys/class/input). And so instead of having class define standard interface for all objects in it we have to rely on something else (struct device_type - not visible fom userspace) to separate them and add tweaks to interface. Can you see that I am not a fan of the design? ;) As far as input concerned - I need to resume input_dev but not evdev, mousedev, tsdev, etc. as they are all just different representations No, it will stay. -- Dmitry -
From: Rafael J. Wysocki <rjw@sisk.pl>
The saved_state member of struct dev_pm_info, defined in include/linux/pm.h, is
not used anywhere, so it can be removed.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
include/linux/pm.h | 1 -
1 file changed, 1 deletion(-)
Index: linux-2.6.22-rc4-mm2/include/linux/pm.h
===================================================================
--- linux-2.6.22-rc4-mm2.orig/include/linux/pm.h
+++ linux-2.6.22-rc4-mm2/include/linux/pm.h
@@ -236,7 +236,6 @@ struct dev_pm_info {
#ifdef CONFIG_PM
unsigned should_wakeup:1;
pm_message_t prev_state;
- void * saved_state;
struct list_head entry;
#endif
};
-
From: Rafael J. Wysocki <rjw@sisk.pl>
The suspend routines should be called for every device during a system sleep
transition, regardless of the device's state, so that drivers can regard these
method calls as notifications that the system is about to go to sleep, rather
than as directives to put their devices into the 'off' state.
This is documented in Documentation/power/devices.txt and is already done in
the core resume code, so it seems reasonable to make the core suspend code
behave accordingly.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
drivers/base/power/suspend.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
Index: linux-2.6.22-rc4-mm2/drivers/base/power/suspend.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/drivers/base/power/suspend.c
+++ linux-2.6.22-rc4-mm2/drivers/base/power/suspend.c
@@ -71,14 +71,13 @@ int suspend_device(struct device * dev,
dev->parent->power.power_state.event);
}
- if (dev->class && dev->class->suspend && !dev->power.power_state.event) {
+ if (dev->class && dev->class->suspend) {
suspend_device_dbg(dev, state, "class ");
error = dev->class->suspend(dev, state);
suspend_report_result(dev->class->suspend, error);
}
- if (!error && dev->bus && dev->bus->suspend
- && !dev->power.power_state.event) {
+ if (!error && dev->bus && dev->bus->suspend) {
suspend_device_dbg(dev, state, "");
error = dev->bus->suspend(dev, state);
suspend_report_result(dev->bus->suspend, error);
@@ -97,8 +96,7 @@ static int suspend_device_late(struct de
{
int error = 0;
- if (dev->bus && dev->bus->suspend_late
- && !dev->power.power_state.event) {
+ if (dev->bus && dev->bus->suspend_late) {
suspend_device_dbg(dev, state, "LATE ");
error = dev->bus->suspend_late(dev, state);
suspend_report_result(dev->bus->suspend_late, error);
-
Did you audit all the drivers to make sure this won't break things? Like for example through inappropriate pci_save_state() calls? I'd really expect this patch would break things... -
Well, in that case I'll have a closer look at them. Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth -
It might not be all that bad. One would expect problems to occur only in cases where devices were already suspended at the time of a system sleep transition. Since relatively few drivers currently implement runtime PM -- and those that do are likely to be more careful about not blindly making state changes -- there might not be too much trouble. Alan Stern -
Yes, in fact I've had no problems related to that so far (tested the patch on four different machines). Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth -
It seems the drivers for which that could be relevant do the checks as needed. Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth -
From: Rafael J. Wysocki <rjw@sisk.pl>
The prev_state member of struct dev_pm_info (defined in include/linux/pm.h) is
only used during a resume to check if the device's state before the suspend was
'off', in which case the device is not resumed. However, in such cases the
decision whether or not to resume the device should be made on the driver level
and the resume callbacks from the device's bus and class should be executed
anyway (the may be needed for some things other than just powering on the
device).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
drivers/base/power/resume.c | 3 +--
drivers/base/power/suspend.c | 2 --
drivers/usb/core/hub.c | 5 -----
drivers/usb/host/ohci-pci.c | 2 --
include/linux/pm.h | 1 -
5 files changed, 1 insertion(+), 12 deletions(-)
Index: linux-2.6.22-rc4-mm2/drivers/base/power/resume.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/drivers/base/power/resume.c
+++ linux-2.6.22-rc4-mm2/drivers/base/power/resume.c
@@ -83,8 +83,7 @@ void dpm_resume(void)
list_move_tail(entry, &dpm_active);
mutex_unlock(&dpm_list_mtx);
- if (!dev->power.prev_state.event)
- resume_device(dev);
+ resume_device(dev);
mutex_lock(&dpm_list_mtx);
put_device(dev);
}
Index: linux-2.6.22-rc4-mm2/drivers/base/power/suspend.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/drivers/base/power/suspend.c
+++ linux-2.6.22-rc4-mm2/drivers/base/power/suspend.c
@@ -71,8 +71,6 @@ int suspend_device(struct device * dev,
dev->parent->power.power_state.event);
}
- dev->power.prev_state = dev->power.power_state;
-
if (dev->class && dev->class->suspend && !dev->power.power_state.event) {
suspend_device_dbg(dev, state, "class ");
error = dev->class->suspend(dev, state);
Index: linux-2.6.22-rc4-mm2/drivers/usb/core/hub.c
===================================================================
--- ...From: Rafael J. Wysocki <rjw@sisk.pl>
The checks if the device's parent is in the right state done in
drivers/base/power/suspend.c and drivers/base/power/resume.c serve no particular
purpose, since if the parent is in a wrong power state, the device's suspend or
resume callbacks are supposed to return an error anyway. Moreover, they are
also useless from the sanity checking point of view, because they rely on the
code being checked to set dev->parent->power.power_state.event appropriately,
which need not happen if that code is buggy. For these reasons they can be
removed.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
---
drivers/base/power/resume.c | 7 -------
drivers/base/power/suspend.c | 7 -------
2 files changed, 14 deletions(-)
Index: linux-2.6.22-rc4-mm2/drivers/base/power/resume.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/drivers/base/power/resume.c
+++ linux-2.6.22-rc4-mm2/drivers/base/power/resume.c
@@ -29,13 +29,6 @@ int resume_device(struct device * dev)
down(&dev->sem);
- if (dev->parent && dev->parent->power.power_state.event) {
- dev_err(dev, "PM: resume from %d, parent %s still %d\n",
- dev->power.power_state.event,
- dev->parent->bus_id,
- dev->parent->power.power_state.event);
- }
-
if (dev->bus && dev->bus->resume) {
dev_dbg(dev,"resuming\n");
error = dev->bus->resume(dev);
Index: linux-2.6.22-rc4-mm2/drivers/base/power/suspend.c
===================================================================
--- linux-2.6.22-rc4-mm2.orig/drivers/base/power/suspend.c
+++ linux-2.6.22-rc4-mm2/drivers/base/power/suspend.c
@@ -63,13 +63,6 @@ int suspend_device(struct device * dev,
dev_dbg(dev, "PM: suspend %d-->%d\n",
dev->power.power_state.event, state.event);
}
- if (dev->parent && dev->parent->power.power_state.event) {
- dev_err(dev,
- "PM: suspend %d->%d, parent %s already ...These are the same as you sent out the other day, right? If so, I'll put them in my tree, trying to catch up on my queue right now. thanks, greg k-h -
Almost. The "PM: Remove pm_parent from struct dev_pm_info" (1/7) has been updated. The "PM: Remove prev_state from struct dev_pm_info" patch (5/7) has been rediffed against 2.6.22-rc4-mm2 (to synchronize with the USB changes in there). OK Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth -
Hmm, patches 1-4 are pretty much obvious cleanups, I guess they can go in. Patches 5+ change semantics of suspend/resume callbacks in subtle way, I guess they need to stay in -mm for a while... Pavel -- (english) http://www.liv