[PATCH] memory: samsung: exynos5422-dmc: Additional locking for 'curr_rate'

From: Lukasz Luba
Date: Tue Aug 11 2020 - 06:17:35 EST


The 'curr_rate' is protected by local 'dmc->lock' in various places, but
not in a function exynos5_dmc_get_status(). The lock protects frequency
(and voltage) change process and the corresponding value stored in
'curr_rate'. Add the locking mechanism to protect the 'curr_rate' reading
also in the exynos5_dmc_get_status().

Suggested-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
Signed-off-by: Lukasz Luba <lukasz.luba@xxxxxxx>
---
drivers/memory/samsung/exynos5422-dmc.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/memory/samsung/exynos5422-dmc.c b/drivers/memory/samsung/exynos5422-dmc.c
index b9c7956e5031..952bc61e68f4 100644
--- a/drivers/memory/samsung/exynos5422-dmc.c
+++ b/drivers/memory/samsung/exynos5422-dmc.c
@@ -908,7 +908,10 @@ static int exynos5_dmc_get_status(struct device *dev,
int ret;

if (dmc->in_irq_mode) {
+ mutex_lock(&dmc->lock);
stat->current_frequency = dmc->curr_rate;
+ mutex_unlock(&dmc->lock);
+
stat->busy_time = dmc->load;
stat->total_time = dmc->total;
} else {
--
2.17.1