On Thu, Feb 19, 2009 at 06:50:52PM -0600, Woodruff, Richard wrote:
> 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.
It sounds to me like clk_set_parent() needs this then to prevent enabled
clocks being reparented. By doing so, we no longer need to disable/enable
the clock within the OMAP2/3 set_parent function since we are now
guaranteed that the clock will be disabled.
Ack?
diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c
index 40cb65b..f49bce9 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 */
diff --git a/arch/arm/plat-omap/clock.c b/arch/arm/plat-omap/clock.c
index 08baa18..b2d9e1f 100644
--- a/arch/arm/plat-omap/clock.c
+++ b/arch/arm/plat-omap/clock.c
@@ -144,12 +144,14 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
return ret;
spin_lock_irqsave(&clockfw_lock, flags);
- if (arch_clock->clk_set_parent)
- ret = arch_clock->clk_set_parent(clk, parent);
- if (ret == 0) {
- if (clk->recalc)
- clk->rate = clk->recalc(clk);
- propagate_rate(clk);
+ if (clk->usecount == 0) {
+ if (arch_clock->clk_set_parent)
+ ret = arch_clock->clk_set_parent(clk, parent);
+ if (ret == 0) {
+ if (clk->recalc)
+ clk->rate = clk->recalc(clk);
+ propagate_rate(clk);
+ }
}
spin_unlock_irqrestore(&clockfw_lock, flags);
--
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