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

From: Ulf Hansson
Date: Wed Mar 14 2018 - 13:08:56 EST


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 <ilina@xxxxxxxxxxxxxx>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
---
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