4.14-stable review patch. If anyone has any objections, please let me know.
------------------ From: Troy Kisky <[email protected]> commit 13bb1d78f2e372ec0d9b30489ac63768240140fc 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 <[email protected]> Signed-off-by: Alexandre Belloni <[email protected]> Cc: Christoph Fritz <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/rtc/rtc-m41t80.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) --- a/drivers/rtc/rtc-m41t80.c +++ b/drivers/rtc/rtc-m41t80.c @@ -155,6 +155,7 @@ struct m41t80_data { #ifdef CONFIG_COMMON_CLK struct clk_hw sqw; unsigned long freq; + unsigned int sqwe; #endif }; @@ -527,7 +528,10 @@ static int m41t80_sqw_control(struct clk else ret &= ~M41T80_ALMON_SQWE; - return i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, ret); + ret = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, ret); + if (!ret) + m41t80->sqwe = enable; + return ret; } static int m41t80_sqw_prepare(struct clk_hw *hw) @@ -542,14 +546,7 @@ static void m41t80_sqw_unprepare(struct static int m41t80_sqw_is_prepared(struct clk_hw *hw) { - struct m41t80_data *m41t80 = sqw_to_m41t80_data(hw); - struct i2c_client *client = m41t80->client; - int ret = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); - - if (ret < 0) - return ret; - - return !!(ret & M41T80_ALMON_SQWE); + return sqw_to_m41t80_data(hw)->sqwe; } static const struct clk_ops m41t80_sqw_ops = {
