On Thursday 17 December 2015 20:40:17 Wolfram Sang wrote: > > > My conclusion for now is: > > > > > > There needs something to be done surely, but currently I don't have the > > > bandwidth to do it or even play around with it. I am not fully happy > > > with your patches as well because __maybe_unused has some kind of "last > > > resort" feeling to me. > > > > I generally like __maybe_unused, but it's a matter of personal preference. > > We could avoid the __maybe_unused if the reg_slave/unreg_slave callback > > pointers are always available in struct i2c_algorithm. > > Yes, I was thinking in this direction, looking at how PM does it. Needs > some playing around, though.
I think PM gets it slightly wrong, the way you have to use #ifdef leads to subtle bugs all the time, and I actually have a patch that converts a few dozen drivers to use __maybe_unused to shut up build warnings and errors. What you can do though is to use a reference like #define __i2c_slave_ptr(x) (IS_ENABLED(CONFIG_I2C_SLAVE) ? (x) : NULL) ... .reg_slave = __i2c_slave_ptr(em_i2c_reg_slave), .unreg_slave = __i2c_slave_ptr(em_i2c_unreg_slave), ... This has the same effect as the __maybe_unused annotation. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html