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    Subject[PATCH AUTOSEL 4.18 085/131] tpm/tpm_i2c_infineon: switch to i2c_lock_bus(..., I2C_LOCK_SEGMENT)
    Date
    From: Peter Rosin <peda@axentia.se>

    [ Upstream commit bb853aac2c478ce78116128263801189408ad2a8 ]

    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>
    Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
    Tested-by: Alexander Steffen <Alexander.Steffen@infineon.com>
    Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
    Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
    ---
    drivers/char/tpm/tpm_i2c_infineon.c | 8 ++++----
    1 file changed, 4 insertions(+), 4 deletions(-)

    diff --git a/drivers/char/tpm/tpm_i2c_infineon.c b/drivers/char/tpm/tpm_i2c_infineon.c
    index 6116cd05e228..9086edc9066b 100644
    --- a/drivers/char/tpm/tpm_i2c_infineon.c
    +++ b/drivers/char/tpm/tpm_i2c_infineon.c
    @@ -117,7 +117,7 @@ static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
    /* Lock the adapter for the duration of the whole sequence. */
    if (!tpm_dev.client->adapter->algo->master_xfer)
    return -EOPNOTSUPP;
    - i2c_lock_adapter(tpm_dev.client->adapter);
    + i2c_lock_bus(tpm_dev.client->adapter, I2C_LOCK_SEGMENT);

    if (tpm_dev.chip_type == SLB9645) {
    /* use a combined read for newer chips
    @@ -192,7 +192,7 @@ static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
    }

    out:
    - i2c_unlock_adapter(tpm_dev.client->adapter);
    + i2c_unlock_bus(tpm_dev.client->adapter, I2C_LOCK_SEGMENT);
    /* take care of 'guard time' */
    usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);

    @@ -224,7 +224,7 @@ static int iic_tpm_write_generic(u8 addr, u8 *buffer, size_t len,

    if (!tpm_dev.client->adapter->algo->master_xfer)
    return -EOPNOTSUPP;
    - i2c_lock_adapter(tpm_dev.client->adapter);
    + i2c_lock_bus(tpm_dev.client->adapter, I2C_LOCK_SEGMENT);

    /* prepend the 'register address' to the buffer */
    tpm_dev.buf[0] = addr;
    @@ -243,7 +243,7 @@ static int iic_tpm_write_generic(u8 addr, u8 *buffer, size_t len,
    usleep_range(sleep_low, sleep_hi);
    }

    - i2c_unlock_adapter(tpm_dev.client->adapter);
    + i2c_unlock_bus(tpm_dev.client->adapter, I2C_LOCK_SEGMENT);
    /* take care of 'guard time' */
    usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);

    --
    2.17.1
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