ARM: OMAP: Add write memory barriers to OMAP2 clock code
After adjusting clock parameters, OMAP2 CPUs need a memory
barrier to make sure the changes go into effect immediately.
Otherwise bad things will happen if we try to access the
peripheral whose clock is just being enabled.
Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c
index 82643a2..302d5a7 100644
--- a/arch/arm/mach-omap2/clock.c
+++ b/arch/arm/mach-omap2/clock.c
@@ -135,6 +135,7 @@
regval32 = __raw_readl(clk->enable_reg);
regval32 |= (1 << clk->enable_bit);
__raw_writel(regval32, clk->enable_reg);
+ wmb();
return 0;
}
@@ -168,6 +169,7 @@
regval32 = __raw_readl(clk->enable_reg);
regval32 &= ~(1 << clk->enable_bit);
__raw_writel(regval32, clk->enable_reg);
+ wmb();
}
static int omap2_clk_enable(struct clk *clk)
@@ -697,12 +699,14 @@
reg_val = __raw_readl(reg);
reg_val &= ~(field_mask << div_off);
reg_val |= (field_val << div_off);
-
__raw_writel(reg_val, reg);
+ wmb();
clk->rate = clk->parent->rate / field_val;
- if (clk->flags & DELAYED_APP)
+ if (clk->flags & DELAYED_APP) {
__raw_writel(0x1, (void __iomem *)&PRCM_CLKCFG_CTRL);
+ wmb();
+ }
ret = 0;
} else if (clk->set_rate != 0)
ret = clk->set_rate(clk, rate);
@@ -838,10 +842,12 @@
reg_val = __raw_readl(reg) & ~(field_mask << src_off);
reg_val |= (field_val << src_off);
__raw_writel(reg_val, reg);
+ wmb();
- if (clk->flags & DELAYED_APP)
+ if (clk->flags & DELAYED_APP) {
__raw_writel(0x1, (void __iomem *)&PRCM_CLKCFG_CTRL);
-
+ wmb();
+ }
if (clk->usecount > 0)
_omap2_clk_enable(clk);