Subject: [PATCH] PM / Domains: Change prototype for the ->attach_dev() callback

From: [email-masked] (Kevin Hilman)
Date: Wed, 05 Nov 2014 15:11:23 -0800

"Rafael J. Wysocki" <[email-masked]> writes:

> On Wednesday, November 05, 2014 02:43:31 PM Kevin Hilman wrote:
>> Dmitry Torokhov <[email-masked]> writes:
>> 
>> > On Thu, Oct 30, 2014 at 01:38:30PM -0700, Kevin Hilman wrote:
>> >> "Rafael J. Wysocki" <[email-masked]> writes:
>> >> 
>> >> > On Thursday, October 30, 2014 01:02:49 PM Ulf Hansson wrote:
>> >> >> Convert the prototype to return and int. This is just an initial step,
>> >> >> needed to support error handling.
>> >> >> 
>> >> >> Signed-off-by: Ulf Hansson <[email-masked]>
>> >> 
>> >> Acked-by: Kevin Hilman <[email-masked]>
>> >> 
>> >> >> 
>> >> >> This patch is intended as fix for 3.18 rc[n]. Why?
>> >> >> 
>> >> >> There are other SOC specific patches around that adds genpd support and which
>> >> >> implements the ->attach_dev() callback. To prevent having an "atomic" patch
>> >> >> during the next release cycle, let's change the prototype now instead.
>> >> >> 
>> >> >> Further patches will add the actual error handling in genpd and these can then
>> >> >> be reviewed and tested thoroughly.
>> >> >
>> >> > So we have no users of ->attach_dev at the moment, right?
>> >> 
>> >> Not in mainline, but there are a couple getting ready to hit -next, so
>> >> we wanted to fix this before they arrive so that adding the error
>> >> handling will be easier.
>> >
>> > BTW, while we are at it, can we also pass the domain itself to
>> > attach_dev() and detach_dev()? If anything it helps with debugging (you
>> > can print domain name from the callbacks).
>> 
>> Agreed, and it makes it match the other callbacks (power_off, power_on)
>> which currently take struct generic_pm_domain *domain.  
>> 
>> Updated version of $SUBJECT patch below.
>
> The subject and changelog need to be updated too IMO.
>

Right.  Here you go.

Kevin

----- >8 ------
>>From c18a6bf3121979c4102ba4f7edb3ac41e3921fc6 Mon Sep 17 00:00:00 2001
From: Ulf Hansson <[email-masked]>
Date: Thu, 30 Oct 2014 13:02:49 +0100
Subject: [PATCH] PM / Domains: Change prototype for the attach and detach
 callbacks

Convert the prototypes to return an int in order to support error
handling in these callbacks.

Also, as suggested by Dmitry Torokhov, pass the domain pointer for use
inside the callbacks, and so that they match the existing
power_on/power_off callbacks which currently take the domain pointer.

Acked-by: Dmitry Torokhov <[email-masked]>
[khilman: added domain as parameter to callbacks, as suggested by Dmitry]
Signed-off-by: Ulf Hansson <[email-masked]>
Signed-off-by: Kevin Hilman <[email-masked]>
---
 drivers/base/power/domain.c | 4 ++--
 include/linux/pm_domain.h   | 6 ++++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 40bc2f4072cc..b520687046d4 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1437,7 +1437,7 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
 	spin_unlock_irq(&dev->power.lock);
 
 	if (genpd->attach_dev)
-		genpd->attach_dev(dev);
+		genpd->attach_dev(genpd, dev);
 
 	mutex_lock(&gpd_data->lock);
 	gpd_data->base.dev = dev;
@@ -1499,7 +1499,7 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd,
 	genpd->max_off_time_changed = true;
 
 	if (genpd->detach_dev)
-		genpd->detach_dev(dev);
+		genpd->detach_dev(genpd, dev);
 
 	spin_lock_irq(&dev->power.lock);
 
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 73e938b7e937..b3ed7766a291 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -72,8 +72,10 @@ struct generic_pm_domain {
 	bool max_off_time_changed;
 	bool cached_power_down_ok;
 	struct gpd_cpuidle_data *cpuidle_data;
-	void (*attach_dev)(struct device *dev);
-	void (*detach_dev)(struct device *dev);
+	int (*attach_dev)(struct generic_pm_domain *domain,
+			  struct device *dev);
+	void (*detach_dev)(struct generic_pm_domain *domain,
+			   struct device *dev);
 };
 
 static inline struct generic_pm_domain *pd_to_genpd(struct dev_pm_domain *pd)
-- 
2.1.0