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[90.63.244.31]) by smtp.gmail.com with ESMTPSA id x185sm52990545wmg.46.2019.07.29.06.02.22 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Mon, 29 Jul 2019 06:02:22 -0700 (PDT) From: Neil Armstrong To: khilman@baylibre.com Cc: Neil Armstrong , linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org, Martin Blumenstingl Subject: [PATCH 1/2] soc: amlogic: meson-clk-measure: protect measure with a mutex Date: Mon, 29 Jul 2019 15:02:17 +0200 Message-Id: <20190729130218.6635-2-narmstrong@baylibre.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190729130218.6635-1-narmstrong@baylibre.com> References: <20190729130218.6635-1-narmstrong@baylibre.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In order to protect clock measuring when multiple process asks for a measure, protect the main measure function with mutexes. Reviewed-by: Kevin Hilman Reviewed-by: Martin Blumenstingl 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; -- 2.22.0