On 21.02.2024 18:19, Wolfram Sang wrote: > Hi Heiner, > >> Note: i801 creates the mux platform device, loading and probing of the >> mux driver may be asynchronous. Therefore we can't call i2c_register_spd() >> for the muxed segments from i801. Instead we have to add a flag to the >> platform data, so that the mux driver knows it's supposed to call >> i2c_register_spd(). > > Has it been considered to use a bus_notifier and check for > BUS_NOTIFY_BOUND_DRIVER? > I checked, and it looks like this: Best would be to check for binding gpio mux driver to platform device "i2c-mux-gpio" has completed. But the bus notification doesn't work for platform devices. Instead we can check for the BUS_NOTIFY_ADD_DEVICE event for the child i2c adapters. This *should* work. I tested that the events are properly recognized. However I don't have hw with a muxed SMBUS, so I can't test the actual functionality. I'll submit a RFC patch. > I'd really like to keep it inside i801 if possible. First, all these > flags in mux drivers only for this corner case are relatively intrusive. > Second, selecting SMBUS for I2C_MUX is also a tad too much for my taste. > > I understand that removing CLASS_SPD is a worthy goal. So, if all fails > we could still try this. But I'd think with bus_notifiers it should be > possible to keep it all in i801. > > Do you think this could work? > > Happy hacking, > > Wolfram > Heiner
