On 10/02/16 18:25, Ulf Hansson wrote: [snip] >>> Perhaps there's a way to allow the generic PM domain to control this >>> by itself. If we for example used the struct device corresponding to >>> the powergate driver, genpd could use it to distinguish between >>> various instances of genpd structs..!? Maybe it would simplify the way >>> to deal with removing domains? >> >> Yes, that would be ideal. However, would have require changing >> genpd_init()? I am not sure how genpd would be able to access the device >> struct for the powergate driver because we don't provide this via any >> API I am aware of? And I am guessing that you don't wish to expose the >> gpd_list to the world either. >> >> If there is an easy way, I am open to it, but looking at it today, I am >> not sure I see a simple way in which we could add a new API to do this. >> However, may be I am missing something! > > If we add a new __pm_genpd_init() API, that could require a struct > device to be provided. That API will thus invoke the existing > pm_genpd_init() but also deal with the extra things needed here. > > I would also allow such an API to return an error code. > > Correspondingly, pm_genpd_remove() could be required to be provided > with a struct device. > > Existing users of pm_genpd_init() can then convert to > __pm_genpd_init() whenever suitable. > > Of course, another option is just to add new member in the genpd > struct for the struct *device. The caller of pm_genpd_init() could > check it, but allow it to be NULL. Although, the pm_genpd_remove() API > would require that pointer to the struct device to be set... > > What do you think? Yes, sounds good. May be it is simpler just to add a new member and let the platform genpd driver handle it. I am wondering if in addition to pm_genpd_remove(), we then just have a function called pm_genpd_remove_tail(), which allows you to pass the struct device pointer and will remove the last pm-domain from the gpd_list and return the genpd pointer if successful. Internally, it will call pm_genpd_remove(). It seems to me that if there are nested pm-domains, then we probably want to remove them starting from the tail as opposed to the head. How does that sound? Cheers Jon -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
