From 4da3782151300237db3abe070f716922889252e0 Mon Sep 17 00:00:00 2001 From: Russell King Date: Tue, 24 Feb 2009 12:46:31 +0000 Subject: [ARM] omap: clk_set_parent: deny changing parent if clock is enabled Richard Woodruff writes: | The historic usage of this has been against single use leaf clocks | (1st instance of gptimer). When it was used it did: | clk_get() | clk_set_parent() | clk_enable() | | This usage was ok for that. Use on a disabled clock is needed. | | If there are multiple users on the clock or it is enabled there are | problems. | | The call can still be unfriendly if 2 different drivers are using the | clock with their own clock get/enable. It might be the function should | return an error if usecount != 0 to stop surprises. It is all around | better if the parenting is done when the clock is off. This is a good reason to ensure that the clock is not enabled when clk_set_parent() is called. Acked-by: Richard Woodruff Signed-off-by: Russell King --- arch/arm/mach-omap2/clock.c | 6 ------ 1 file changed, 6 deletions(-) (limited to 'arch/arm/mach-omap2/clock.c') diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c index 40cb65ba1fac..f49bce997a0b 100644 --- a/arch/arm/mach-omap2/clock.c +++ b/arch/arm/mach-omap2/clock.c @@ -807,9 +807,6 @@ int omap2_clk_set_parent(struct clk *clk, struct clk *new_parent) if (!parent_div) return -EINVAL; - if (clk->usecount > 0) - _omap2_clk_disable(clk); - /* Set new source value (previous dividers if any in effect) */ v = __raw_readl(clk->clksel_reg); v &= ~clk->clksel_mask; @@ -819,9 +816,6 @@ int omap2_clk_set_parent(struct clk *clk, struct clk *new_parent) _omap2xxx_clk_commit(clk); - if (clk->usecount > 0) - _omap2_clk_enable(clk); - clk_reparent(clk, new_parent); /* CLKSEL clocks follow their parents' rates, divided by a divisor */ -- cgit v1.2.3