| Message ID | 20190701091258.3870-6-narmstrong@baylibre.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | arm64: g12a: add support for DVFS | expand |
Hi Neil, On Mon, Jul 1, 2019 at 11:13 AM Neil Armstrong <narmstrong@baylibre.com> wrote: > > 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> > Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> > --- > drivers/soc/amlogic/meson-clk-measure.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/drivers/soc/amlogic/meson-clk-measure.c b/drivers/soc/amlogic/meson-clk-measure.c > index 19d4cbc93a17..c470e24f1dfa 100644 > --- a/drivers/soc/amlogic/meson-clk-measure.c > +++ b/drivers/soc/amlogic/meson-clk-measure.c > @@ -11,6 +11,8 @@ > #include <linux/debugfs.h> > #include <linux/regmap.h> > > +static DEFINE_MUTEX(measure_lock); I wonder if that should be part of struct meson_msr for consistency reasons apart from that: Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
diff --git a/drivers/soc/amlogic/meson-clk-measure.c b/drivers/soc/amlogic/meson-clk-measure.c index 19d4cbc93a17..c470e24f1dfa 100644 --- a/drivers/soc/amlogic/meson-clk-measure.c +++ b/drivers/soc/amlogic/meson-clk-measure.c @@ -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;