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rtc: m41t80: avoid i2c read in m41t80_sqw_is_prepared
commit 13bb1d78f2
upstream.
This is a little more efficient and avoids the warning
WARNING: possible circular locking dependency detected
4.14.0-rc7-00010 #16 Not tainted
------------------------------------------------------
kworker/2:1/70 is trying to acquire lock:
(prepare_lock){+.+.}, at: [<c049300c>] clk_prepare_lock+0x80/0xf4
but task is already holding lock:
(i2c_register_adapter){+.+.}, at: [<c0690b04>]
i2c_adapter_lock_bus+0x14/0x18
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (i2c_register_adapter){+.+.}:
rt_mutex_lock+0x44/0x5c
i2c_adapter_lock_bus+0x14/0x18
i2c_transfer+0xa8/0xbc
i2c_smbus_xfer+0x20c/0x5d8
i2c_smbus_read_byte_data+0x38/0x48
m41t80_sqw_is_prepared+0x18/0x28
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: Christoph Fritz <chf.fritz@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
11118640ae
commit
7623bd95a6
1 changed files with 6 additions and 9 deletions
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@ -155,6 +155,7 @@ struct m41t80_data {
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#ifdef CONFIG_COMMON_CLK
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struct clk_hw sqw;
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unsigned long freq;
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unsigned int sqwe;
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#endif
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};
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@ -527,7 +528,10 @@ static int m41t80_sqw_control(struct clk_hw *hw, bool enable)
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else
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ret &= ~M41T80_ALMON_SQWE;
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return i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, ret);
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ret = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, ret);
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if (!ret)
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m41t80->sqwe = enable;
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return ret;
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}
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static int m41t80_sqw_prepare(struct clk_hw *hw)
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@ -542,14 +546,7 @@ static void m41t80_sqw_unprepare(struct clk_hw *hw)
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static int m41t80_sqw_is_prepared(struct clk_hw *hw)
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{
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struct m41t80_data *m41t80 = sqw_to_m41t80_data(hw);
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struct i2c_client *client = m41t80->client;
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int ret = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
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if (ret < 0)
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return ret;
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return !!(ret & M41T80_ALMON_SQWE);
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return sqw_to_m41t80_data(hw)->sqwe;
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}
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static const struct clk_ops m41t80_sqw_ops = {
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