On 12.12.2017 at 20:03, Peter Rosin wrote: > [Adding Wolfram] > > On 2017-12-12 18:14, Adrian Fiergolski wrote: >> On 12.12.2017 at 16:25, Peter Rosin wrote: >>> On 2017-12-12 13:06, Adrian Fiergolski wrote: >>>> In a normal run scenario, I don't need it. I can imagine it may be a >>>> problem, if the module >>>> is suddenly unloaded and loaded: the mux remains set to some not default >>>> bus and >>>> the module is not aware of it. However, I agree then the bus could be >>>> reset somewhere >>>> at higher level. >>> Think about what happens if you have more than one chip on some i2c bus >>> that uses this reset mechanism. First you instantiate one of the drivers >>> and both chips are reset. Then you carry on with careful configuration >>> of that first chip. Then you instantiate the driver for the other chip >>> and all you careful configuration of the first chip is lost as it is >>> reset a second time. So, you just can't reset everything on the bus in >>> any random driver, that has to be done on some other level. >> That's all true. However, we are discussing an I2C mux/switch which is a >> root >> of an I2C sub-tree. It is initialized first, so the SOFTWARE_RESET command >> would reset only mux/switch and all its nodes. The command would be followed >> by the configuration of all its nodes, which anyway can't be performed >> earlier. > Have a look at Documentation/i2c/i2c-topology and think again. And... ? Cheers, Adrian
