[PATCH 5.2 301/413] opp: Dont use IS_ERR on invalid supplies

From: Greg Kroah-Hartman
Date: Wed Jul 24 2019 - 15:39:30 EST


From: Dmitry Osipenko <digetx@xxxxxxxxx>

commit 560d1bcad715c215e7ffe5d7cffe045974b623d0 upstream.

_set_opp_custom() receives a set of OPP supplies as its arguments and
the caller of it passes NULL when the supplies are not valid. But
_set_opp_custom(), by mistake, checks for error by performing
IS_ERR(old_supply) on it which will always evaluate to false.

The problem was spotted during of testing of upcoming update for the
NVIDIA Tegra CPUFreq driver.

Cc: stable <stable@xxxxxxxxxxxxxxx>
Fixes: 7e535993fa4f ("OPP: Separate out custom OPP handler specific code")
Reported-by: Marc Dietrich <marvin24@xxxxxx>
Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
[ Viresh: Massaged changelog ]
Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/opp/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -682,7 +682,7 @@ static int _set_opp_custom(const struct

data->old_opp.rate = old_freq;
size = sizeof(*old_supply) * opp_table->regulator_count;
- if (IS_ERR(old_supply))
+ if (!old_supply)
memset(data->old_opp.supplies, 0, size);
else
memcpy(data->old_opp.supplies, old_supply, size);