diff mbox

[V2,01/10] PM / OPP: Fix memory leak while adding duplicate OPPs

Message ID c4517fb2db294f2da5f6e306091c230210f51a75.1481085478.git.viresh.kumar@linaro.org
State Accepted
Commit 7f8538ebaefc075f364f14a4f4852b1885ed897c
Headers show

Commit Message

Viresh Kumar Dec. 7, 2016, 4:41 a.m. UTC
There are two types of duplicate OPPs that get different behavior from
the core:
A). An earlier OPP is marked 'available' and has same freq/voltages as
    the new one.
B). An earlier OPP with same frequency, but is marked 'unavailable' OR
    doesn't have same voltages as the new one.

The OPP core returns 0 for the first one, but -EEXIST for the second.

While the OPP core returns 0 for the first case, its callers don't free
the newly allocated OPP structure which isn't used anymore. Fix that by
returning -EBUSY instead of 0, but make the callers return 0 eventually.

As this isn't a critical fix, its not getting marked for stable kernel.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

---
 drivers/base/power/opp/core.c | 18 ++++++++++++++++--
 drivers/base/power/opp/of.c   |  6 +++++-
 2 files changed, 21 insertions(+), 3 deletions(-)

-- 
2.7.1.410.g6faf27b

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Comments

Stephen Boyd Dec. 22, 2016, 12:39 a.m. UTC | #1
On 12/07, Viresh Kumar wrote:
> There are two types of duplicate OPPs that get different behavior from

> the core:

> A). An earlier OPP is marked 'available' and has same freq/voltages as


perhaps just "A)" instead of "A)."

>     the new one.

> B). An earlier OPP with same frequency, but is marked 'unavailable' OR

>     doesn't have same voltages as the new one.

> 

> The OPP core returns 0 for the first one, but -EEXIST for the second.

> 

> While the OPP core returns 0 for the first case, its callers don't free

> the newly allocated OPP structure which isn't used anymore. Fix that by

> returning -EBUSY instead of 0, but make the callers return 0 eventually.

> 

> As this isn't a critical fix, its not getting marked for stable kernel.

> 

> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

> ---


Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>


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diff mbox

Patch

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index a0e6294baf1d..9ff816217c6e 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -1080,6 +1080,16 @@  static bool _opp_supported_by_regulators(struct dev_pm_opp *opp,
 	return true;
 }
 
+/*
+ * Returns:
+ * 0: On success. And appropriate error message for duplicate OPPs.
+ * -EBUSY: For OPP with same freq/volt and is available. The callers of
+ *  _opp_add() must return 0 if they receive -EBUSY from it. This is to make
+ *  sure we don't print error messages unnecessarily if different parts of
+ *  kernel try to initialize the OPP table.
+ * -EEXIST: For OPP with same freq but different volt or is unavailable. This
+ *  should be considered an error by the callers of _opp_add().
+ */
 int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
 	     struct opp_table *opp_table)
 {
@@ -1112,7 +1122,7 @@  int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
 
 		/* Should we compare voltages for all regulators here ? */
 		return opp->available &&
-		       new_opp->supplies[0].u_volt == opp->supplies[0].u_volt ? 0 : -EEXIST;
+		       new_opp->supplies[0].u_volt == opp->supplies[0].u_volt ? -EBUSY : -EEXIST;
 	}
 
 	new_opp->opp_table = opp_table;
@@ -1186,8 +1196,12 @@  int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt,
 	new_opp->dynamic = dynamic;
 
 	ret = _opp_add(dev, new_opp, opp_table);
-	if (ret)
+	if (ret) {
+		/* Don't return error for duplicate OPPs */
+		if (ret == -EBUSY)
+			ret = 0;
 		goto free_opp;
+	}
 
 	mutex_unlock(&opp_table_lock);
 
diff --git a/drivers/base/power/opp/of.c b/drivers/base/power/opp/of.c
index 3f7d2591b173..356c75edd656 100644
--- a/drivers/base/power/opp/of.c
+++ b/drivers/base/power/opp/of.c
@@ -327,8 +327,12 @@  static int _opp_add_static_v2(struct device *dev, struct device_node *np)
 		goto free_opp;
 
 	ret = _opp_add(dev, new_opp, opp_table);
-	if (ret)
+	if (ret) {
+		/* Don't return error for duplicate OPPs */
+		if (ret == -EBUSY)
+			ret = 0;
 		goto free_opp;
+	}
 
 	/* OPP to select on device suspend */
 	if (of_property_read_bool(np, "opp-suspend")) {