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authorSaravana Kannan <saravanak@google.com>2019-12-06 11:17:26 -0800
committerJohn Stultz <john.stultz@linaro.org>2021-05-10 19:53:27 +0000
commit186b863f013276dc5745fa6c7c9e40598389162a (patch)
treed50ddf500cb3c1479869a91ff130abf173bcbd13
parent8590e193814569fddf39c9e456240feea7f2ef7b (diff)
downloadandroid-dev-186b863f013276dc5745fa6c7c9e40598389162a.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 2a6ab606e1e5..7525b3360b38 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);