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[90.63.244.31]) by smtp.gmail.com with ESMTPSA id o126sm6802520wmo.1.2019.06.20.08.00.24 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 20 Jun 2019 08:00:25 -0700 (PDT) From: Neil Armstrong To: jbrunet@baylibre.com, khilman@baylibre.com Cc: linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, martin.blumenstingl@googlemail.com, Neil Armstrong Subject: [RFC/RFT 05/14] soc: amlogic: meson-clk-measure: protect measure with a mutex Date: Thu, 20 Jun 2019 17:00:04 +0200 Message-Id: <20190620150013.13462-6-narmstrong@baylibre.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190620150013.13462-1-narmstrong@baylibre.com> References: <20190620150013.13462-1-narmstrong@baylibre.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org In order to protect clock measuring when multiple process asks for a mesure, protect the main measure function with mutexes. Signed-off-by: Neil Armstrong --- 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 #include +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; -- 2.21.0