[PATCH 4.19 216/220] PM / devfreq: Fix static checker warning in try_then_request_governor

From: Greg Kroah-Hartman
Date: Fri Nov 22 2019 - 06:06:23 EST

From: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>

[ Upstream commit b53b0128052ffd687797d5f4deeb76327e7b5711 ]

The patch 23c7b54ca1cd: "PM / devfreq: Fix devfreq_add_device() when
drivers are built as modules." leads to the following static checker

drivers/devfreq/devfreq.c:1043 governor_store()
warn: 'governor' can also be NULL

The reason is that the try_then_request_governor() function returns both
error pointers and NULL. It should just return error pointers, so fix
this by returning a ERR_PTR to the error intead of returning NULL.

Fixes: 23c7b54ca1cd ("PM / devfreq: Fix devfreq_add_device() when drivers are built as modules.")
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
Reviewed-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
Signed-off-by: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
drivers/devfreq/devfreq.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index bcd2279106760..e2ab46bfa666e 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -231,7 +231,7 @@ static struct devfreq_governor *find_devfreq_governor(const char *name)
* if is not found. This can happen when both drivers (the governor driver
* and the driver that call devfreq_add_device) are built as modules.
* devfreq_list_lock should be held by the caller. Returns the matched
- * governor's pointer.
+ * governor's pointer or an error pointer.
static struct devfreq_governor *try_then_request_governor(const char *name)
@@ -257,7 +257,7 @@ static struct devfreq_governor *try_then_request_governor(const char *name)
/* Restore previous state before return */
if (err)
- return NULL;
+ return ERR_PTR(err);

governor = find_devfreq_governor(name);