PM / Domains: Add "wait for parent" status for generic PM domains
The next patch will make it possible for a generic PM domain to have
multiple parents (i.e. multiple PM domains it depends on). To
prepare for that change it is necessary to change pm_genpd_poweron()
so that it doesn't jump to the start label after running itself
recursively for the parent domain. For this purpose, introduce a new
PM domain status value GPD_STATE_WAIT_PARENT that will be set by
pm_genpd_poweron() before calling itself recursively for the parent
domain and modify the code in drivers/base/power/domain.c so that
the GPD_STATE_WAIT_PARENT status is guaranteed to be preserved during
the execution of pm_genpd_poweron() for the parent.
This change also causes pm_genpd_add_subdomain() and
pm_genpd_remove_subdomain() to wait for started pm_genpd_poweron() to
complete and allows pm_genpd_runtime_resume() to avoid dropping the
lock after powering on the PM domain.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 81c5782..97e3f8e 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -13,6 +13,7 @@
enum gpd_status {
GPD_STATE_ACTIVE = 0, /* PM domain is active */
+ GPD_STATE_WAIT_PARENT, /* PM domain's parent is being waited for */
GPD_STATE_BUSY, /* Something is happening to the PM domain */
GPD_STATE_REPEAT, /* Power off in progress, to be repeated */
GPD_STATE_POWER_OFF, /* PM domain is off */