user/sven/linux.git/include/linux/pm_domain.h, branch v4.9.5

PM / Domains: Add support for removing nested PM domains by provider

2016-09-13T00:49:34Z

If a device supports PM domains that are subdomains of another PM domain, then the PM domains should be removed in reverse order to ensure that the subdomains are removed first. Furthermore, if there is more than one provider, then there needs to be a way to remove the domains in reverse order for a specific provider. Add the function of_genpd_remove_last() to remove the last PM domain added by a given PM domain provider and return the generic_pm_domain structure for the PM domain that was removed. Signed-off-by: Jon Hunter Acked-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM / Domains: Add support for removing PM domains

2016-09-13T00:49:34Z

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. Note that the bulk of the code that removes the PM domain is placed in a separate local function genpd_remove() (which is called by pm_genpd_remove()). The code is structured in this way to prepare for adding another function to remove a PM domain by provider that will also call genpd_remove(). Note that users of genpd_remove() must call this function with the mutex, gpd_list_lock, held. PM domains can only be removed if the associated provider has been removed, they are not a parent domain to another PM domain and have no devices associated with them. Signed-off-by: Jon Hunter Acked-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM / Domains: Store the provider in the PM domain structure

2016-09-13T00:49:34Z

It is possible that a device has more than one provider of PM domains and to support the removal of a PM domain by provider, it is necessary to store a reference to the provider in the PM domain structure. Therefore, store a reference to the firmware node handle in the PM domain structure and populate it when providers (only device-tree based providers are currently supported by PM domains) are registered. Please note that when removing PM domains, it is necessary to verify that the PM domain provider has been removed from the list of providers before the PM domain can be removed. To do this add another member to the PM domain structure that indicates if the provider is present and set this member accordingly when providers are added and removed. Initialise the 'provider' and 'has_provider' members of the generic_pm_domain structure when a PM domains is added by calling pm_genpd_init(). Signed-off-by: Jon Hunter Acked-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM / Domains: Don't expose xlate and provider helper functions

2016-09-13T00:49:33Z

Functions __of_genpd_xlate_simple(), __of_genpd_xlate_onecell() and __of_genpd_add_provider() are not used outside of the core generic PM domain code. Therefore, reduce the number of APIs exposed by making these static. At the same time don't expose the typedef for genpd_xlate_t either and make this a local definition as well. The functions are renamed to follow the naming conventions for static functions in the generic PM domain core. Signed-off-by: Jon Hunter Acked-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM / Domains: Don't expose generic_pm_domain structure to clients

2016-09-13T00:49:33Z

There should be no need to expose the generic_pm_domain structure to clients and this eliminates the need to implement reference counting for any external reference to a PM domain. Therefore, make the functions pm_genpd_lookup_dev() and of_genpd_get_from_provider() private to the PM domain core. The functions are renamed in accordance with the naming conventions for genpd static functions. Signed-off-by: Jon Hunter Acked-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM / Domains: Add new helper functions for device-tree

2016-09-13T00:49:32Z

Ideally, if we are returning a reference to a PM domain via a call to of_genpd_get_from_provider(), then we should keep track of such references via a reference count. The reference count could then be used to determine if a PM domain can be safely removed. Alternatively, it is possible to avoid such external references by providing APIs to access the PM domain and hence, eliminate any calls to of_genpd_get_from_provider(). Add new helper functions for adding a device and a subdomain to a PM domain when using device-tree, so that external calls to of_genpd_get_from_provider() can be removed. Signed-off-by: Jon Hunter Acked-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki

PM / Domains: Convert pm_genpd_init() to return an error code

2016-06-29T00:15:19Z

The are already cases when pm_genpd_init() can fail. Currently we hide the failures instead of propagating an error code, which is a better method. Moreover, to prepare for future changes like moving away from using a fixed array-size of the struct genpd_power_state, to instead dynamically allocate data for it, the pm_genpd_init() API needs to be able to return an error code, as allocation can fail. Current users of the pm_genpd_init() is thus requested to start dealing with error codes. In the transition phase, users will have to live with only error messages being printed to log. Signed-off-by: Ulf Hansson Acked-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki

PM / Domains: Allow genpd to power on during system PM phases

2016-06-16T13:01:43Z

If a PM domain is powered off when the first device starts its system PM prepare phase, genpd prevents any further attempts to power on the PM domain during the following system PM phases. Not until the system PM complete phase is finalized for all devices in the PM domain, genpd again allows it to be powered on. This behaviour needs to be changed, as a subsystem/driver for a device in the same PM domain may still need to be able to serve requests in some of the system PM phases. Accordingly, it may need to runtime resume its device and thus also request the corresponding PM domain to be powered on. To deal with these scenarios, let's make the device operational in the system PM prepare phase by runtime resuming it, no matter if the PM domain is powered on or off. Changing this also enables us to remove genpd's suspend_power_off flag, as it's being used to track this condition. Additionally, we must allow the PM domain to be powered on via runtime PM during the system PM phases. This change also requires a fix in the AMD ACP (Audio CoProcessor) drm driver. It registers a genpd to model the ACP as a PM domain, but unfortunately it's also abuses genpd's "internal" suspend_power_off flag to deal with a corner case at system PM resume. More precisely, the so called SMU block powers on the ACP at system PM resume, unconditionally if it's being used or not. This may lead to that genpd's internal status of the power state, may not correctly reflect the power state of the HW after a system PM resume. Because of changing the behaviour of genpd, by runtime resuming devices in the prepare phase, the AMD ACP drm driver no longer have to deal with this corner case. So let's just drop the related code in this driver. Signed-off-by: Ulf Hansson Reviewed-by: Kevin Hilman Acked-by: Maruthi Bayyavarapu Signed-off-by: Rafael J. Wysocki

PM / Domains: Remove ->save|restore_state() callbacks

2016-04-22T00:29:17Z

As a part of the ongoing consolidation of genpd, it's become questionable whether clients actually needs to be able to assign their own set of ->save|restore_state() callbacks. Currently all users copes fine with the default callbacks, so let's remove the configuration option and stick to the default ones. This enables further clarifications of the related code and let's also rename pm_genpd_default_save|restore_state() into __genpd_runtime_suspend|resume() to apply the rule of static functionnames in genpd. Signed-off-by: Ulf Hansson Reviewed-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki

PM / Domains: Rename stop_ok to suspend_ok for the genpd governor

2016-04-22T00:29:17Z

The genpd governor validates the latency constraints to find out whether it's acceptable to runtime suspend a device. Earlier this validation was made to know whether it was okay to invoke the ->stop() callback for the device, hence the governor used the name "stop_ok" for the related variables. To clarify the code around this, let's rename these variables from "stop_ok" to "suspend_ok". Signed-off-by: Ulf Hansson Reviewed-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki