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soc: amlogic: meson-clk-measure: protect measure with a mutex

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In order to protect clock measuring when multiple process asks for
a measure, protect the main measure function with mutexes.

Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
This commit is contained in:
Neil Armstrong 2019-07-29 15:02:17 +02:00 committed by Kevin Hilman
parent 5f9e832c13
commit 3a760d9865
1 changed files with 11 additions and 1 deletions
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12
drivers/soc/amlogic/meson-clk-measure.c
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@ -11,6 +11,8 @@
#include <linux/debugfs.h>
#include <linux/regmap.h>
static DEFINE_MUTEX(measure_lock);
#define MSR_CLK_DUTY 0x0
#define MSR_CLK_REG0 0x4
#define MSR_CLK_REG1 0x8
@ -360,6 +362,10 @@ static int meson_measure_id(struct meson_msr_id *clk_msr_id,
unsigned int val;
int ret;
ret = mutex_lock_interruptible(&measure_lock);
if (ret)
return ret;
regmap_write(priv->regmap, MSR_CLK_REG0, 0);
/* Set measurement duration */
@ -377,8 +383,10 @@ static int meson_measure_id(struct meson_msr_id *clk_msr_id,
ret = regmap_read_poll_timeout(priv->regmap, MSR_CLK_REG0,
val, !(val & MSR_BUSY), 10, 10000);
if (ret)
if (ret) {
mutex_unlock(&measure_lock);
return ret;
}
/* Disable */
regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_ENABLE, 0);
@ -386,6 +394,8 @@ static int meson_measure_id(struct meson_msr_id *clk_msr_id,
/* Get the value in multiple of gate time counts */
regmap_read(priv->regmap, MSR_CLK_REG2, &val);
mutex_unlock(&measure_lock);
if (val >= MSR_VAL_MASK)
return -EINVAL;