On Mon, 7 Aug 2023 17:54:07 +0300 Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote: > On Sun, Aug 06, 2023 at 02:29:50PM +0100, Jonathan Cameron wrote: > > On Sat, 5 Aug 2023 17:42:21 +0000 > > Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote: > > > > On Fri, 4 Aug 2023 17:17:24 +0100 > > > > Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote: > > ... > > > > + * Besides the fact that some drivers abuse the device ID driver_data type > > > + * and claim it to be integer, for the bus specific ID tables the driver_data > > > + * may be defined as kernel_ulong_t. For these tables 0 is a valid response, > > > + * but not for this function. It's recommended to convert those either to avoid > > > + * 0 or use a real pointer to the predefined driver data. > > > We still need to maintain consistency across the two tables, which > > is a stronger requirement than avoiding 0. > > True. Any suggestion how to amend the above comment? Because the documentation > makes sense on its own (may be split from the series?). For bus ID tables it is fine right now as long as no one checks for NULL. I guess adding this to the i2c_get_match_data and spi equivalent wrapper functions might avoid someone shooting themselves in the foot (I've done it for starters more than once). > > > Some drivers already do that by forcing the enum used to start at 1 which > > doesn't solver the different data types issue. > > And some maintainers do not want to see non-enum values in i2c ID table. > *Shrug*. > That leaves us stuck unless we move to a form where the i2c ID table isn't used if there is an of_device_id table (or maybe we invent yet another table and if that is present it is used for dt and were i2c_device_id is used and hence becomes an opt in? That will also be tricky however. Jonathan
