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Commit 80784cba authored by Peter Rosin's avatar Peter Rosin Committed by Greg Kroah-Hartman
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mfd: 88pm860x-i2c: switch to i2c_lock_bus(..., I2C_LOCK_SEGMENT) 



[ Upstream commit 8c8f74f3 ]

Locking the root adapter for __i2c_transfer will deadlock if the
device sits behind a mux-locked I2C mux. Switch to the finer-grained
i2c_lock_bus with the I2C_LOCK_SEGMENT flag. If the device does not
sit behind a mux-locked mux, the two locking variants are equivalent.

Signed-off-by: default avatarPeter Rosin <peda@axentia.se>
Acked-by: default avatarLee Jones <lee.jones@linaro.org>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
Signed-off-by: default avatarSasha Levin <alexander.levin@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4101e59a

drivers/mfd/88pm860x-i2c.c

+4 −4
Original line number Diff line number Diff line
@@ -146,14 +146,14 @@ int pm860x_page_reg_write(struct i2c_client *i2c, int reg, 
	unsigned char zero;

	int ret;



	i2c_lock_adapter(i2c->adapter);

	i2c_lock_bus(i2c->adapter, I2C_LOCK_SEGMENT);

	read_device(i2c, 0xFA, 0, &zero);

	read_device(i2c, 0xFB, 0, &zero);

	read_device(i2c, 0xFF, 0, &zero);

	ret = write_device(i2c, reg, 1, &data);

	read_device(i2c, 0xFE, 0, &zero);

	read_device(i2c, 0xFC, 0, &zero);

	i2c_unlock_adapter(i2c->adapter);

	i2c_unlock_bus(i2c->adapter, I2C_LOCK_SEGMENT);

	return ret;

}

EXPORT_SYMBOL(pm860x_page_reg_write);
@@ -164,14 +164,14 @@ int pm860x_page_bulk_read(struct i2c_client *i2c, int reg, 
	unsigned char zero = 0;

	int ret;



	i2c_lock_adapter(i2c->adapter);

	i2c_lock_bus(i2c->adapter, I2C_LOCK_SEGMENT);

	read_device(i2c, 0xfa, 0, &zero);

	read_device(i2c, 0xfb, 0, &zero);

	read_device(i2c, 0xff, 0, &zero);

	ret = read_device(i2c, reg, count, buf);

	read_device(i2c, 0xFE, 0, &zero);

	read_device(i2c, 0xFC, 0, &zero);

	i2c_unlock_adapter(i2c->adapter);

	i2c_unlock_bus(i2c->adapter, I2C_LOCK_SEGMENT);

	return ret;

}

EXPORT_SYMBOL(pm860x_page_bulk_read);