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由 Ulf Hansson 提交于
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: NUlf Hansson <ulf.hansson@linaro.org> Reviewed-by: NKevin Hilman <khilman@baylibre.com> Acked-by: NMaruthi Bayyavarapu <maruthi.bayyavarapu@amd.com> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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