4.9-stable review patch. If anyone has any objections, please let me know.
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From: Peter Rosin peda@axentia.se
[ Upstream commit 8c8f74f327a76604a499fad8c54c15e1c0ee8051 ]
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: Peter Rosin peda@axentia.se Acked-by: Lee Jones lee.jones@linaro.org Signed-off-by: Wolfram Sang wsa@the-dreams.de Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/mfd/88pm860x-i2c.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/mfd/88pm860x-i2c.c +++ b/drivers/mfd/88pm860x-i2c.c @@ -146,14 +146,14 @@ int pm860x_page_reg_write(struct i2c_cli 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_cli 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);