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 193c2a07cfaacb9249ab0e3d34bce32490879355 ]
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: Dmitry Torokhov dmitry.torokhov@gmail.com 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/input/touchscreen/rohm_bu21023.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/input/touchscreen/rohm_bu21023.c +++ b/drivers/input/touchscreen/rohm_bu21023.c @@ -304,7 +304,7 @@ static int rohm_i2c_burst_read(struct i2 msg[1].len = len; msg[1].buf = buf;
- i2c_lock_adapter(adap); + i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
for (i = 0; i < 2; i++) { if (__i2c_transfer(adap, &msg[i], 1) < 0) { @@ -313,7 +313,7 @@ static int rohm_i2c_burst_read(struct i2 } }
- i2c_unlock_adapter(adap); + i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);
return ret; }