On 2018-12-21 15:50, Wolfram Sang wrote: > >>>> I think this might be as simple as adding: >>>> >>>> if (WARN_ON(adap->dev.parent->power.is_suspended)) >>>> return -ESHUTDOWN; > > Peter, I think this should work for muxes, too, or? The i2c_transfer() > call to the mux will not be rejected, but it will be later when we reach > the root adapter. And then the error code will be pushed down the tree > until we arrive at the mux again. So, the rejection will not happen at > the earliest time, but it will happen. Is my understanding correct? Yes, I agree with that analysis. All mux actions eventually end up with an __i2c_transfer() call on the relevant root adapter. Hmm, but not *all* calls. How about SMBus adapters? Should there not be a similar WARN_ON in __i2c_smbus_xfer? But maybe that's not applicable for some reason? Just asking... Cheers, Peter
