fix(rpi3): tighten platform pwr_domain_pwr_down_wfi behaviour
Platforms which implement pwr_domain_pwr_down_wfi differ substantially
in behaviour. However, different cpus require similar sequences to power
down. This patch tightens the behaviour of these platforms to end on a
wfi loop after performing platform power down. This is required so that
platforms behave more consistently on power down, in cases where the wfi
can fall through.
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: Ie29bd3a5e654780bacb4e07a6d123ac6d2467c1f
diff --git a/docs/getting_started/porting-guide.rst b/docs/getting_started/porting-guide.rst
index be4833b..6996c17 100644
--- a/docs/getting_started/porting-guide.rst
+++ b/docs/getting_started/porting-guide.rst
@@ -2769,7 +2769,8 @@
The ``target_state`` has a similar meaning as described in the ``pwr_domain_off()``
operation and it encodes the platform coordinated target local power states for
the CPU power domain and its parent power domain levels. This function must
-not return back to the caller.
+not return back to the caller (by calling wfi in an infinite loop to ensure
+some CPUs power down mitigations work properly).
If this function is not implemented by the platform, PSCI generic
implementation invokes ``psci_power_down_wfi()`` for power down.