Messages in this thread | | | Date | Sat, 28 Jan 2012 16:00:11 +0000 | From | Russell King - ARM Linux <> | Subject | Re: [PATCH] Fix LPC32XX's clock.c |
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On Fri, Jan 27, 2012 at 03:17:48PM +0100, Roland Stigge wrote: > @@ -382,30 +388,62 @@ static u32 local_clk_usbpll_setup(struct clk_pll_setup *pHCLKPllSetup) > static int local_usbpll_enable(struct clk *clk, int enable) > { > u32 reg; > - int ret = -ENODEV; > - unsigned long timeout = 1 + msecs_to_jiffies(10); > + int ret = 0; > + unsigned long timeout = jiffies + msecs_to_jiffies(20);
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> - /* Wait for PLL lock */ > - while ((timeout > jiffies) & (ret == -ENODEV)) { > + /* > + * Enable PLL > + */ > + reg |= LPC32XX_CLKPWR_USBCTRL_PLL_PWRUP; > + __raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL); > + > + /* > + * Wait for PLL to lock > + */ > + while ((timeout > jiffies) && (ret == -ENODEV)) {
This is buggy - it's waiting to go wrong when jiffies wraps. You really want to use time_before() or time_after() to make these comparisons, which are safe against wrap-around.
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