Messages in this thread Patch in this message | | | From | stigge@antcom ... | Subject | [PATCH v3 7/7] ARM: LPC32xx: clock.c: Fix mutex lock issues | Date | Thu, 2 Feb 2012 20:19:48 +0100 |
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This patch fixes the mutex issue in clock.c, as done in Kevin Wells' original driver update:
In some cases, the clock drivers could grab a mutex twice in an improper context. This patch changes the mutex mechanism to a simple irq lock/unlock mechanism and removes un-needed locks from some functions.
(See also git.lpclinux.com)
Signed-off-by: Roland Stigge <stigge@antcom.de> Tested-by: Wolfram Sang <w.sang@pengutronix.de>
diff --git a/arch/arm/mach-lpc32xx/clock.c b/arch/arm/mach-lpc32xx/clock.c index 0606a63..0e01bf4 100644 --- a/arch/arm/mach-lpc32xx/clock.c +++ b/arch/arm/mach-lpc32xx/clock.c @@ -98,9 +98,10 @@ #include "clock.h" #include "common.h" +static DEFINE_SPINLOCK(global_clkregs_lock); + static struct clk clk_armpll; static struct clk clk_usbpll; -static DEFINE_MUTEX(clkm_lock); /* * Post divider values for PLLs based on selected register value @@ -892,16 +893,6 @@ static struct clk clk_lcd = { .enable_mask = LPC32XX_CLKPWR_LCDCTRL_CLK_EN, }; -static inline void clk_lock(void) -{ - mutex_lock(&clkm_lock); -} - -static inline void clk_unlock(void) -{ - mutex_unlock(&clkm_lock); -} - static void local_clk_disable(struct clk *clk) { /* Don't attempt to disable clock if it has no users */ @@ -946,10 +937,11 @@ static int local_clk_enable(struct clk *clk) int clk_enable(struct clk *clk) { int ret; + unsigned long flags; - clk_lock(); + spin_lock_irqsave(&global_clkregs_lock, flags); ret = local_clk_enable(clk); - clk_unlock(); + spin_unlock_irqrestore(&global_clkregs_lock, flags); return ret; } @@ -960,9 +952,11 @@ EXPORT_SYMBOL(clk_enable); */ void clk_disable(struct clk *clk) { - clk_lock(); + unsigned long flags; + + spin_lock_irqsave(&global_clkregs_lock, flags); local_clk_disable(clk); - clk_unlock(); + spin_unlock_irqrestore(&global_clkregs_lock, flags); } EXPORT_SYMBOL(clk_disable); @@ -971,13 +965,7 @@ EXPORT_SYMBOL(clk_disable); */ unsigned long clk_get_rate(struct clk *clk) { - unsigned long rate; - - clk_lock(); - rate = clk->get_rate(clk); - clk_unlock(); - - return rate; + return clk->get_rate(clk); } EXPORT_SYMBOL(clk_get_rate); @@ -993,11 +981,8 @@ int clk_set_rate(struct clk *clk, unsigned long rate) * the actual rate set as part of the peripheral dividers * instead of high level clock control */ - if (clk->set_rate) { - clk_lock(); + if (clk->set_rate) ret = clk->set_rate(clk, rate); - clk_unlock(); - } return ret; } @@ -1008,15 +993,11 @@ EXPORT_SYMBOL(clk_set_rate); */ long clk_round_rate(struct clk *clk, unsigned long rate) { - clk_lock(); - if (clk->round_rate) rate = clk->round_rate(clk, rate); else rate = clk->get_rate(clk); - clk_unlock(); - return rate; } EXPORT_SYMBOL(clk_round_rate);
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