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| author |   Wolfram Sang <wsa+renesas@sang-engineering.com> | 2019-04-03 14:40:18 +0200 |
|---|---|---|
| committer |   Wolfram Sang <wsa@the-dreams.de> | 2019-04-16 13:08:16 +0200 |
| commit | 8927fbf481248954ca1fc5e652171936b94905ac (patch) | |
| tree | 4369d913802a91c0a21ed3d911fa3cf2dfb423b3 | |
| parent | i2c: stu300: use xfer_atomic callback to bail out early (diff) | |
| download | linux-dev-8927fbf481248954ca1fc5e652171936b94905ac.tar.xz linux-dev-8927fbf481248954ca1fc5e652171936b94905ac.zip | |
i2c: algo: bit: add flag to whitelist atomic transfers
Use the new xfer_atomic callback to check a newly introduced flag to
whitelist atomic transfers. This will report configurations which
worked accidently.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| -rw-r--r-- | drivers/i2c/algos/i2c-algo-bit.c | 22 | ||||
| -rw-r--r-- | include/linux/i2c-algo-bit.h | 1 |
2 files changed, 21 insertions, 2 deletions
diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c index 5e5990a83da5..913db013fe90 100644 --- a/drivers/i2c/algos/i2c-algo-bit.c +++ b/drivers/i2c/algos/i2c-algo-bit.c @@ -603,6 +603,23 @@ bailout: return ret; } +/* + * We print a warning when we are not flagged to support atomic transfers but + * will try anyhow. That's what the I2C core would do as well. Sadly, we can't + * modify the algorithm struct at probe time because this struct is exported + * 'const'. + */ +static int bit_xfer_atomic(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[], + int num) +{ + struct i2c_algo_bit_data *adap = i2c_adap->algo_data; + + if (!adap->can_do_atomic) + dev_warn(&i2c_adap->dev, "not flagged for atomic transfers\n"); + + return bit_xfer(i2c_adap, msgs, num); +} + static u32 bit_func(struct i2c_adapter *adap) { return I2C_FUNC_I2C | I2C_FUNC_NOSTART | I2C_FUNC_SMBUS_EMUL | @@ -615,8 +632,9 @@ static u32 bit_func(struct i2c_adapter *adap) /* -----exported algorithm data: ------------------------------------- */ const struct i2c_algorithm i2c_bit_algo = { - .master_xfer = bit_xfer, - .functionality = bit_func, + .master_xfer = bit_xfer, + .master_xfer_atomic = bit_xfer_atomic, + .functionality = bit_func, }; EXPORT_SYMBOL(i2c_bit_algo); diff --git a/include/linux/i2c-algo-bit.h b/include/linux/i2c-algo-bit.h index 69045df78e2d..7fd5575a368f 100644 --- a/include/linux/i2c-algo-bit.h +++ b/include/linux/i2c-algo-bit.h @@ -33,6 +33,7 @@ struct i2c_algo_bit_data { minimum 5 us for standard-mode I2C and SMBus, maximum 50 us for SMBus */ int timeout; /* in jiffies */ + bool can_do_atomic; /* callbacks don't sleep, we can be atomic */ }; int i2c_bit_add_bus(struct i2c_adapter *); |