On Thu, Dec 17, 2020 at 4:02 PM Barnabás Pőcze <pobrn@xxxxxxxxxxxxxx> wrote: > > 2020. december 17., csütörtök 14:36 keltezéssel, Rafael J. Wysocki <rafael@xxxxxxxxxx> írta: > > > [...] > > > >> My thinking here that I shouldn't make assumptions for future platform > > > >> implementations - there may be valid cases in the future where being > > > >> able to return an error condition if there was an error would be useful. > > > >> > > > >> Just trying to keep this somewhat future proof. Returning an error > > > >> condition seemed a useful thing to have available. > > > > > > > > You can still return an error while returning a platform_profile_option value. > > > > > > > > Just add a special value representing an error to that set. > > > > > > > I'd like to understand what is better about that approach than having an > > > error and a returnable parameter? > > > > > > I'm probably missing something obvious but if I add an extra > > > platform_profile option (e.g PLATFORM_PROFILE_ERROR) to be used in an > > > error case (and return just an enum platform_profile_option) it seems I > > > lose the granularity of being able to return a specific error condition. > > > It doesn't feel like an improvement. > > > > And what's the user expected to do about the different error codes > > that can be returned? > > Even assuming the users of the API cannot or will not handle different errors > differently, who would benefit from getting rid of this information which may be > an aid in debugging for those who know what they're looking at? > > And if a new enum value is introduced to signal an error condition, how is that > going to be communicated to the users? A magic string like "error" or "-1"? > Or under a single errno like -EIO? Yes. > Personally, I believe neither of these two > solutions are better than returning the actual errno which is deemed most > appropriate by the platform profile handler. Or am I missing a third way? Can we please defer this until we actually have a driver needing to return different error values from ->get_profile() (and I find it hard to believe that there will be any drivers like that)? Let's do the simpler thing until we have a real need to do the more complicated one. Otherwise we're preparing for things that may never happen.
