[PATCH v4 4/7] ARM: LPC32xx: clock.c: jiffies wrapping

Roland Stigge stigge at antcom.de
Wed Feb 8 15:41:02 EST 2012


This patch fixes the jiffies wrapping bug in clock.c.

It corrects the timeout computation based on jiffies, uses time_before() for
correct wrapping handling and replaces a binary "&" which should really be a
logical "&&" in a truth expression.

Signed-off-by: Roland Stigge <stigge at antcom.de>
Acked-by: Wolfram Sang <w.sang at pengutronix.de> 
Tested-by: Wolfram Sang <w.sang at pengutronix.de>
Acked-by: Kevin Wells <kevin.wells at nxp.com>

diff --git a/arch/arm/mach-lpc32xx/clock.c b/arch/arm/mach-lpc32xx/clock.c
index 8e79313..f64c9a1 100644
--- a/arch/arm/mach-lpc32xx/clock.c
+++ b/arch/arm/mach-lpc32xx/clock.c
@@ -128,7 +128,7 @@ static struct clk osc_32KHz = {
 static int local_pll397_enable(struct clk *clk, int enable)
 {
 	u32 reg;
-	unsigned long timeout = 1 + msecs_to_jiffies(10);
+	unsigned long timeout = jiffies + msecs_to_jiffies(10);
 
 	reg = __raw_readl(LPC32XX_CLKPWR_PLL397_CTRL);
 
@@ -143,7 +143,7 @@ static int local_pll397_enable(struct clk *clk, int enable)
 		/* Wait for PLL397 lock */
 		while (((__raw_readl(LPC32XX_CLKPWR_PLL397_CTRL) &
 			LPC32XX_CLKPWR_SYSCTRL_PLL397_STS) == 0) &&
-			(timeout > jiffies))
+			time_before(jiffies, timeout))
 			cpu_relax();
 
 		if ((__raw_readl(LPC32XX_CLKPWR_PLL397_CTRL) &
@@ -157,7 +157,7 @@ static int local_pll397_enable(struct clk *clk, int enable)
 static int local_oscmain_enable(struct clk *clk, int enable)
 {
 	u32 reg;
-	unsigned long timeout = 1 + msecs_to_jiffies(10);
+	unsigned long timeout = jiffies + msecs_to_jiffies(10);
 
 	reg = __raw_readl(LPC32XX_CLKPWR_MAIN_OSC_CTRL);
 
@@ -172,7 +172,7 @@ static int local_oscmain_enable(struct clk *clk, int enable)
 		/* Wait for main oscillator to start */
 		while (((__raw_readl(LPC32XX_CLKPWR_MAIN_OSC_CTRL) &
 			LPC32XX_CLKPWR_MOSC_DISABLE) != 0) &&
-			(timeout > jiffies))
+			time_before(jiffies, timeout))
 			cpu_relax();
 
 		if ((__raw_readl(LPC32XX_CLKPWR_MAIN_OSC_CTRL) &
@@ -384,7 +384,7 @@ static int local_usbpll_enable(struct clk *clk, int enable)
 {
 	u32 reg;
 	int ret = -ENODEV;
-	unsigned long timeout = 1 + msecs_to_jiffies(10);
+	unsigned long timeout = jiffies + msecs_to_jiffies(10);
 
 	reg = __raw_readl(LPC32XX_CLKPWR_USB_CTRL);
 
@@ -397,7 +397,7 @@ static int local_usbpll_enable(struct clk *clk, int enable)
 		__raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL);
 
 		/* Wait for PLL lock */
-		while ((timeout > jiffies) & (ret == -ENODEV)) {
+		while (time_before(jiffies, timeout) && (ret == -ENODEV)) {
 			reg = __raw_readl(LPC32XX_CLKPWR_USB_CTRL);
 			if (reg & LPC32XX_CLKPWR_USBCTRL_PLL_STS)
 				ret = 0;



More information about the linux-arm-kernel mailing list