media: tda18271: switch to i2c_lock_bus(..., I2C_LOCK_SEGMENT)
authorPeter Rosin <peda@axentia.se>
Wed, 20 Jun 2018 05:18:01 +0000 (07:18 +0200)
committerWolfram Sang <wsa@the-dreams.de>
Thu, 12 Jul 2018 22:09:32 +0000 (00:09 +0200)
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: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
drivers/media/tuners/tda18271-common.c

index 7e81cd8..054b3b7 100644 (file)
@@ -225,7 +225,7 @@ static int __tda18271_write_regs(struct dvb_frontend *fe, int idx, int len,
         */
        if (lock_i2c) {
                tda18271_i2c_gate_ctrl(fe, 1);
-               i2c_lock_adapter(priv->i2c_props.adap);
+               i2c_lock_bus(priv->i2c_props.adap, I2C_LOCK_SEGMENT);
        }
        while (len) {
                if (max > len)
@@ -246,7 +246,7 @@ static int __tda18271_write_regs(struct dvb_frontend *fe, int idx, int len,
                len -= max;
        }
        if (lock_i2c) {
-               i2c_unlock_adapter(priv->i2c_props.adap);
+               i2c_unlock_bus(priv->i2c_props.adap, I2C_LOCK_SEGMENT);
                tda18271_i2c_gate_ctrl(fe, 0);
        }
 
@@ -300,7 +300,7 @@ int tda18271_init_regs(struct dvb_frontend *fe)
         * as those could cause bad things
         */
        tda18271_i2c_gate_ctrl(fe, 1);
-       i2c_lock_adapter(priv->i2c_props.adap);
+       i2c_lock_bus(priv->i2c_props.adap, I2C_LOCK_SEGMENT);
 
        /* initialize registers */
        switch (priv->id) {
@@ -516,7 +516,7 @@ int tda18271_init_regs(struct dvb_frontend *fe)
        /* synchronize */
        __tda18271_write_regs(fe, R_EP1, 1, false);
 
-       i2c_unlock_adapter(priv->i2c_props.adap);
+       i2c_unlock_bus(priv->i2c_props.adap, I2C_LOCK_SEGMENT);
        tda18271_i2c_gate_ctrl(fe, 0);
 
        return 0;