On 9 September 2016 at 17:17, Jon Hunter <jonathanh@xxxxxxxxxx> wrote: > > On 09/09/16 14:54, Jon Hunter wrote: >> On 08/09/16 12:49, Ulf Hansson wrote: >>> On 16 August 2016 at 11:49, Jon Hunter <jonathanh@xxxxxxxxxx> wrote: >>>> The genpd framework allows users to add PM domains via the pm_genpd_init() >>>> function, however, there is no corresponding function to remove a PM >>>> domain. For most devices this may be fine as the PM domains are never >>>> removed, however, for devices that wish to populate the PM domains from >>>> within a driver, having the ability to remove a PM domain if the probing >>>> of the device fails or the driver is unloaded is necessary. >>>> >>>> Add the function pm_genpd_remove() to remove a PM domain by referencing >>>> it's generic_pm_domain structure. >>>> >>>> PM domains can only be removed if they are not a parent domain to >>>> another PM domain and have no devices associated with them. >>> >>> I think we should also check if the there's is a provider registered >>> for the genpd, as it should also prevent the genpd from being removed. >>> Right? >> >> Yes I would agree. I had thought that after patch #4 of this series that >> only the provider itself would be able to call this. However, we should >> probably still verify that the provider has correctly remove itself. > > So now I have the following. I am still not 100% happy. I cannot clear > the ->provider when calling of_genpd_del_provider() and so I cannot use > this to verify if the provider is present and so I need to check the > list of providers and it gets a bit messy. I have been wracking my > brains to find a better alternative (including a single function to > remove the provider and domains at once but there are issues with that > as well). Instead of using the ->provider pointer to know whether the genpd has a valid provider, why not just add an additional ->has_provider bool flag in the genpd struct? Simply set the flag when adding the provider and reset it when removing it. Wouldn't that work? > > I think that long term it may make sense to reference the providers > exclusively by the fwnode_handle and make the list of provider non-DT > specific. I could do it now, but it would increase the series. Perhaps a good idea. Although I agree, let's not make that change as a part of this series. [...] Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
