On Mon, Jul 17, 2023 at 06:45:27PM +0000, Biju Das wrote: > Hi Dmitry, > > > Subject: Re: [PATCH v2 1/2] Input: exc3000 - Simplify probe() > > > > On Mon, Jul 17, 2023 at 07:15:50PM +0100, Mark Brown wrote: > > > On Mon, Jul 17, 2023 at 04:35:02PM +0000, Biju Das wrote: > > > > > > > The .device_get_match_data callbacks are missing for I2C and SPI bus > > subsystems. > > > > Can you please throw some lights on this? > > > > > > It's the first time I've ever heard of that callback, I don't know why > > > whoever added it wouldn't have done those buses in particular or if it > > > just didn't happen. Try adding it and if it works send the patches? > > > > I think there is a disconnect. Right now device_get_match_data callbacks > > are part of fwnode_operations. I was proposing to add another optional > > device_get_match_data callback to 'struct bus_type' to allow individual > > buses control how match data is handled, before (or after) jumping into > > the fwnode-backed device_get_match_data callbacks. > > That is what implemented here [1] and [2] right? > > [1] https://elixir.bootlin.com/linux/v6.5-rc2/source/drivers/i2c/i2c-core-base.c#L117 > [2] https://elixir.bootlin.com/linux/v6.5-rc2/source/drivers/spi/spi.c#L364 > > First it check for fwnode-backed device_get_match_data callbacks and > Fallback is bus-type based match. > > Looks like you are proposing to unify [1] and [2] and you want the > logic to be other way around. ie, first bus-type match, then > fwnode-backed callbacks? > I do not have a strong preference for the ordering, i.e. I think it is perfectly fine to do the generic fwnode-based lookup and if there is no match have bus method called as a fallback, but I do not want driver writers to learn about multiple <bus-prefix>_get_match_data() implementations, I would prefer if they could call device_get_match_data() and the right thing happened in all cases. Thanks. -- Dmitry
