Thread (40 messages) 40 messages, 4 authors, 2018-04-18
STALE3011d
Revisions (7)
  1. v6 current
  2. v7 [diff vs current]
  3. v8 [diff vs current]
  4. v10 [diff vs current]
  5. v11 [diff vs current]
  6. v12 [diff vs current]
  7. v13 [diff vs current]

[PATCH v6 01/25] PM / Domains: Don't treat zero found compatible idle states as an error

From: Ulf Hansson <hidden>
Date: 2018-03-14 17:08:52
Also in: linux-arm-msm, linux-pm, lkml
Subsystem: driver core, kobjects, debugfs and sysfs, hibernation (aka software suspend, aka swsusp), power management core, suspend to ram, the rest · Maintainers: Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Linus Torvalds

Instead of returning -EINVAL from of_genpd_parse_idle_states() in case none
compatible states was found, let's return 0 to indicate success. Assign
also the out-parameter *states to NULL and *n to 0, to indicate to the
caller that zero states have been found/allocated.

This enables the caller of of_genpd_parse_idle_states() to easier act on
the returned error code.

Cc: Lina Iyer <redacted>
Signed-off-by: Ulf Hansson <redacted>
---
 drivers/base/power/domain.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 1ea0e25..c2ef944 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -2331,8 +2331,8 @@ static int genpd_iterate_idle_states(struct device_node *dn,
  *
  * Returns the device states parsed from the OF node. The memory for the states
  * is allocated by this function and is the responsibility of the caller to
- * free the memory after use. If no domain idle states is found it returns
- * -EINVAL and in case of errors, a negative error code.
+ * free the memory after use. If any or zero compatible domain idle states is
+ * found it returns 0 and in case of errors, a negative error code is returned.
  */
 int of_genpd_parse_idle_states(struct device_node *dn,
 			struct genpd_power_state **states, int *n)
@@ -2341,8 +2341,14 @@ int of_genpd_parse_idle_states(struct device_node *dn,
 	int ret;
 
 	ret = genpd_iterate_idle_states(dn, NULL);
-	if (ret <= 0)
-		return ret < 0 ? ret : -EINVAL;
+	if (ret < 0)
+		return ret;
+
+	if (!ret) {
+		*states = NULL;
+		*n = 0;
+		return 0;
+	}
 
 	st = kcalloc(ret, sizeof(*st), GFP_KERNEL);
 	if (!st)
-- 
2.7.4
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