On Mon, Jan 09, 2023 at 01:35:29PM +0100, Michael Walle wrote: > Hi Russell, > > Am 2023-01-03 23:19, schrieb Russell King (Oracle): > > On Tue, Jan 03, 2023 at 11:21:08AM +0100, Michael Walle wrote: > > > Am 2023-01-03 11:13, schrieb Russell King (Oracle): > > > > On Wed, Dec 28, 2022 at 12:07:19AM +0100, Michael Walle wrote: > > > > > + if (!bus || !bus->name) > > > > > + return -EINVAL; > > > > > + > > > > > + /* An access method always needs both read and write operations */ > > > > > + if ((bus->read && !bus->write) || > > > > > + (!bus->read && bus->write) || > > > > > + (bus->read_c45 && !bus->write_c45) || > > > > > + (!bus->read_c45 && bus->write_c45)) > > > > > > > > I wonder whether the following would be even more readable: > > > > > > > > if (!bus->read != !bus->write || !bus->read_c45 != !bus->write_c45) > > > > > > That's what Andrew had originally. But there was a comment from > > > Sergey [1] > > > which I agree with. I had a hard time wrapping my head around that, > > > so I > > > just listed all the possible bad cases. > > > > The only reason I suggested it was because when looked at your code, > > it also took several reads to work out what it was trying to do! > > > > Would using !!bus->read != !!bus->write would help or make it worse, > > !!ptr being the more normal way to convert something to a boolean? > > IMHO that makes it even harder. But I doubt we will find an expression > that will work for everyone. I'll go with your suggestion/Andrew's first > version in the next iteration. I think the double negation conveys the intention better than the simple one, actually (maybe even xor instead of != ?). In terms of readability I think I prefer the way the patch is written right now, but if you keep the comment, the double negation should be pretty easy to swallow too.
