clk: Allow clocks to be marked as CRITICAL (32b9b109) · Commits · 戴 / test

Critical clocks are those which must not be gated, else undefined or catastrophic failure would occur. Here we have chosen to ensure the prepare/enable counts are correctly incremented, so as not to confuse users with enabled clocks with no visible users. Signed-off-by:

Lee Jones <lee.jones@linaro.org> Signed-off-by:

Michael Turquette <mturquette@baylibre.com> Link: lkml.kernel.org/r/1455225554-13267-2-git-send-email-mturquette@baylibre.com

drivers/clk/clk.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -2397,6 +2397,11 @@ static int __clk_core_init(struct clk_core *core)
		if (core->ops->init)
		core->ops->init(core->hw);

		if (core->flags & CLK_IS_CRITICAL) {
		clk_core_prepare(core);
		clk_core_enable(core);
		}

		kref_init(&core->ref);
		out:
		clk_prepare_unlock();

include/linux/clk-provider.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -32,6 +32,7 @@
		#define CLK_GET_ACCURACY_NOCACHE BIT(8) /* do not use the cached clk accuracy */
		#define CLK_RECALC_NEW_RATES BIT(9) /* recalc rates after notifications */
		#define CLK_SET_RATE_UNGATE BIT(10) /* clock needs to run to set rate */
		#define CLK_IS_CRITICAL BIT(11) /* do not gate, ever */

		struct clk;
		struct clk_hw;

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