From 0a036388529477bcce01226a8ba901ef16333393 Mon Sep 17 00:00:00 2001 From: Peter Chen Date: Tue, 16 Jul 2013 10:23:20 +0800 Subject: [PATCH] ARM: imx: clk-pllv3: improve the timeout waiting method There are two improvements for this commit: - Add comparing pll lock condition after while loop. It can fix potential fake timeout problem caused by the code is just scheduled out before compare the timeout, and the time of scheduling out are more than one jiffies. - Move timeout assignment more close to compare the timeout. It can reduce the possibility the code is scheduled out, and the timeout can be more precise. Signed-off-by: Peter Chen Acked-by: Sascha Hauer Signed-off-by: Shawn Guo --- arch/arm/mach-imx/clk-pllv3.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/arch/arm/mach-imx/clk-pllv3.c b/arch/arm/mach-imx/clk-pllv3.c index a9fad5f8d340..f6640b6a7b31 100644 --- a/arch/arm/mach-imx/clk-pllv3.c +++ b/arch/arm/mach-imx/clk-pllv3.c @@ -48,7 +48,7 @@ struct clk_pllv3 { static int clk_pllv3_prepare(struct clk_hw *hw) { struct clk_pllv3 *pll = to_clk_pllv3(hw); - unsigned long timeout = jiffies + msecs_to_jiffies(10); + unsigned long timeout; u32 val; val = readl_relaxed(pll->base); @@ -59,12 +59,19 @@ static int clk_pllv3_prepare(struct clk_hw *hw) val &= ~BM_PLL_POWER; writel_relaxed(val, pll->base); + timeout = jiffies + msecs_to_jiffies(10); /* Wait for PLL to lock */ - while (!(readl_relaxed(pll->base) & BM_PLL_LOCK)) + do { + if (readl_relaxed(pll->base) & BM_PLL_LOCK) + break; if (time_after(jiffies, timeout)) - return -ETIMEDOUT; + break; + } while (1); - return 0; + if (readl_relaxed(pll->base) & BM_PLL_LOCK) + return 0; + else + return -ETIMEDOUT; } static void clk_pllv3_unprepare(struct clk_hw *hw) -- 2.34.1