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authorSaravana Kannan <saravanak@google.com>2019-12-06 11:17:26 -0800
committerJohn Stultz <john.stultz@linaro.org>2021-06-07 21:31:50 +0000
commitef80d0c1159ca752a37e1b8b769dd47028c1ce92 (patch)
tree71c975c94128e21e0bd990d2682b6b2641396093
parentae0387db1ed10549fe90fe0c2ead480a2d40cbe0 (diff)
downloadandroid-dev-ef80d0c1159ca752a37e1b8b769dd47028c1ce92.tar.gz
ANDROID: GKI: clk: Don't disable unused clocks with sync state support
Some clocks (that are left on at boot) of a clock provider with sync state support might not have their "state held" during clock registration because they remain orphans even after all the clocks in the clock provider are registered. These are typically clocks whose current parent is registered by a different clock provider. When the other clock providers are registered, these orphan clocks get adopted (no longer orphans) and will have their "state held". However if the clock provider of the parent clocks are modules, then these orphan clocks would get turned off during late_initcall_sync() because they'd look like unused clocks at that point. This might turn off clocks that are in use by an active hardware block and cause system issues. To avoid this, don't turn off an unused clock if its clock provider has sync state support and the clock doesn't have the CLK_DONT_HOLD_STATE flag set. Bug: 144066914 Signed-off-by: Saravana Kannan <saravanak@google.com> Change-Id: I1f1dbca4994a5b7085930996e1cc5e848266436c
-rw-r--r--drivers/clk/clk.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 1aaba5f411d4..2617e2cdca32 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1217,6 +1217,10 @@ static void __init clk_unprepare_unused_subtree(struct clk_core *core)
hlist_for_each_entry(child, &core->children, child_node)
clk_unprepare_unused_subtree(child);
+ if (dev_has_sync_state(core->dev) &&
+ !(core->flags & CLK_DONT_HOLD_STATE))
+ return;
+
if (core->prepare_count)
return;
@@ -1248,6 +1252,10 @@ static void __init clk_disable_unused_subtree(struct clk_core *core)
hlist_for_each_entry(child, &core->children, child_node)
clk_disable_unused_subtree(child);
+ if (dev_has_sync_state(core->dev) &&
+ !(core->flags & CLK_DONT_HOLD_STATE))
+ return;
+
if (core->flags & CLK_OPS_PARENT_ENABLE)
clk_core_prepare_enable(core->parent);