diff mbox

PM / Domains: Convert pm_genpd_init() to return an error code

Message ID 1466159272-9726-1-git-send-email-ulf.hansson@linaro.org
State Accepted
Commit 7eb231c337e00735d4b553ed4ae7f9441598f028
Headers show

Commit Message

Ulf Hansson June 17, 2016, 10:27 a.m. UTC 
The are already cases when pm_genpd_init() can fail. Currently we hide the
failures instead of propagating an error code, which is a better method.

Moreover, to prepare for future changes like moving away from using a
fixed array-size of the struct genpd_power_state, to instead dynamically
allocate data for it, the pm_genpd_init() API needs to be able to return
an error code, as allocation can fail.

Current users of the pm_genpd_init() is thus requested to start dealing
with error codes. In the transition phase, users will have to live with
only error messages being printed to log.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

---
 drivers/base/power/domain.c | 10 +++++++---
 include/linux/pm_domain.h   |  9 +++++----
 2 files changed, 12 insertions(+), 7 deletions(-)

-- 
1.9.1

Comments

Ulf Hansson June 20, 2016, 11:17 a.m. UTC | #1 
On 17 June 2016 at 12:59, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> Hi Ulf,

>

> On Fri, Jun 17, 2016 at 12:27 PM, Ulf Hansson <ulf.hansson@linaro.org> wrote:

>> The are already cases when pm_genpd_init() can fail. Currently we hide the

>> failures instead of propagating an error code, which is a better method.

>>

>> Moreover, to prepare for future changes like moving away from using a

>> fixed array-size of the struct genpd_power_state, to instead dynamically

>> allocate data for it, the pm_genpd_init() API needs to be able to return

>> an error code, as allocation can fail.

>>

>> Current users of the pm_genpd_init() is thus requested to start dealing

>> with error codes. In the transition phase, users will have to live with

>> only error messages being printed to log.

>

> What can we do in case of error? It's not like anything is going to work

> if PM domains are failing...


I guess that would depend on the SoC and what particular PM domain
that would be failing.

Due to that, I would prefer to allow the user to be able to act on
errors - currently they can't.

Kind regards
Uffe
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diff mbox

Patch

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 9193aac..a1f2aff 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1258,12 +1258,14 @@  EXPORT_SYMBOL_GPL(pm_genpd_remove_subdomain);
  * @genpd: PM domain object to initialize.
  * @gov: PM domain governor to associate with the domain (may be NULL).
  * @is_off: Initial value of the domain's power_is_off field.
+ *
+ * Returns 0 on successful initialization, else a negative error code.
  */
-void pm_genpd_init(struct generic_pm_domain *genpd,
-		   struct dev_power_governor *gov, bool is_off)
+int pm_genpd_init(struct generic_pm_domain *genpd,
+		  struct dev_power_governor *gov, bool is_off)
 {
 	if (IS_ERR_OR_NULL(genpd))
-		return;
+		return -EINVAL;
 
 	INIT_LIST_HEAD(&genpd->master_links);
 	INIT_LIST_HEAD(&genpd->slave_links);
@@ -1321,6 +1323,8 @@  void pm_genpd_init(struct generic_pm_domain *genpd,
 	mutex_lock(&gpd_list_lock);
 	list_add(&genpd->gpd_list_node, &gpd_list);
 	mutex_unlock(&gpd_list_lock);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(pm_genpd_init);
 
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index dd5b044..31fec85 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -127,8 +127,8 @@  extern int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
 				  struct generic_pm_domain *new_subdomain);
 extern int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
 				     struct generic_pm_domain *target);
-extern void pm_genpd_init(struct generic_pm_domain *genpd,
-			  struct dev_power_governor *gov, bool is_off);
+extern int pm_genpd_init(struct generic_pm_domain *genpd,
+			 struct dev_power_governor *gov, bool is_off);
 
 extern struct dev_power_governor simple_qos_governor;
 extern struct dev_power_governor pm_domain_always_on_gov;
@@ -163,9 +163,10 @@  static inline int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
 {
 	return -ENOSYS;
 }
-static inline void pm_genpd_init(struct generic_pm_domain *genpd,
-				 struct dev_power_governor *gov, bool is_off)
+static inline int pm_genpd_init(struct generic_pm_domain *genpd,
+				struct dev_power_governor *gov, bool is_off)
 {
+	return -ENOSYS;
 }
 #endif