[PATCH 3/3] PM / Domains: Enable genpd_dev_pm_attach_by_id|name() for single PM domain

[Ulf Hansson <ulf.hansson@linaro.org>]

If a call to dev_pm_domain_attach() succeeds to attach a device to its
single PM domain, the important point is to prevent following calls to
dev_pm_domain_attach_by_name|id() to fail. This is managed by checking the
dev->pm_domain pointer and then return -EEXIST, rather than continue
calling genpd_dev_pm_attach_by_id|name().

For this reason, let's enable genpd_dev_pm_attach_by_id|name() to be used
for also single PM domains. This simplifies for future users to solely make
use of dev_pm_domain_attach_by_id|name() rather than having to combine it
with dev_pm_domain_attach().

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 drivers/base/power/domain.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 801f31c87d16..1b026704a8fc 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -2512,10 +2512,10 @@ struct device *genpd_dev_pm_attach_by_id(struct device *dev,
 	if (!dev->of_node)
 		return NULL;
 
-	/* Deal only with devices using multiple PM domains. */
+	/* Verify that the index is within a valid range. */
 	num_domains = of_count_phandle_with_args(dev->of_node, "power-domains",
 						 "#power-domain-cells");
-	if (num_domains < 2 || index >= num_domains)
+	if (index >= num_domains)
 		return NULL;
 
 	/* Allocate and register device on the genpd bus. */
-- 
2.17.1