On Friday 05 June 2009, Magnus Damm wrote: > On Wed, Jun 3, 2009 at 6:01 PM, Rafael J. Wysocki<rjw@xxxxxxx> wrote: > > On Tuesday 02 June 2009, Magnus Damm wrote: > >> If you guys dislike adding arch specific data to struct platform > >> device then for SuperH we can just (mis)use the arch specific data in > >> struct device instead. I'm afraid that solution wastes memory since > >> the data will only be used for platform devices anyway. So I prefer > >> adding arch specific data to struct platform_device instead of struct > >> device if possible. > > > > BTW, what is the difference really? You can always put > > dev.platform_data = NULL for devices that don't have any platform data, > > can't you? > > So the convention is that dev.platform_data points to driver-specific > data. It may or may not be required by the driver. The format of this > data is driver specific and should be the same across architectures. > > What I'm trying to add with struct pdev_archdata is a place for > architecture specific data. This data is needed by architecture > specific code (for example runtime PM), and since it's architecture > specific it should _never_ be touched by device driver code. Exactly > like struct dev_archdata but for platform devices. > > Like I said, we _could_ use struct device for this purpose, but it > sounds like suboptimal software design to me. Using struct device > means that we put data where it doesn't belong. I'd like to add > _platform_ _device_ _specific_ data, not data that should be present > in all struct devices in the system but only used in some cases. OK, that explains the idea. Perhaps it's woth putting into the changelog? Best, Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
