[PATCH AUTOSEL 5.4 027/330] PM / devfreq: tegra30: Fix integer overflow on CPU's freq max out

Sasha Levin
2020-09-18T03:14:50Z

From: Dmitry Osipenko <digetx@gmail.com>

[ Upstream commit 53b4b2aeee26f42cde5ff2a16dd0d8590c51a55a ]

There is another kHz-conversion bug in the code, resulting in integer
overflow. Although, this time the resulting value is 4294966296 and it's
close to ULONG_MAX, which is okay in this case.

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Tested-by: Peter Geis <pgwipeout@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/devfreq/tegra30-devfreq.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
index a6ba75f4106d8..e273011c83fbd 100644
--- a/drivers/devfreq/tegra30-devfreq.c
+++ b/drivers/devfreq/tegra30-devfreq.c
@@ -68,6 +68,8 @@

#define KHZ 1000

+#define KHZ_MAX (ULONG_MAX / KHZ)
+
/* Assume that the bus is saturated if the utilization is 25% */
#define BUS_SATURATION_RATIO 25

@@ -169,7 +171,7 @@ struct tegra_actmon_emc_ratio {
};

static struct tegra_actmon_emc_ratio actmon_emc_ratios[] = {
- { 1400000, ULONG_MAX },
+ { 1400000, KHZ_MAX },
{ 1200000, 750000 },
{ 1100000, 600000 },
{ 1000000, 500000 },
--
2.25.1