[PATCH] memory: samsung: exynos5422-dmc: Additional locking for 'curr_rate'
From: Lukasz Luba <lukasz.luba@arm.com>
Date: 2020-08-11 10:16:56
Also in:
linux-pm, linux-samsung-soc, lkml
Subsystem:
arm/samsung s3c, s5p and exynos arm architectures, dmc frequency driver for samsung exynos5422, memory controller drivers, the rest · Maintainers:
Krzysztof Kozlowski, Peter Griffin, Lukasz Luba, Linus Torvalds
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@kernel.org> Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> --- 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
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