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-rw-r--r--arch/arm/mach-mmp/time.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/arch/arm/mach-mmp/time.c b/arch/arm/mach-mmp/time.c
index 41b2e8abc9e6..708816caf859 100644
--- a/arch/arm/mach-mmp/time.c
+++ b/arch/arm/mach-mmp/time.c
@@ -43,18 +43,21 @@
static void __iomem *mmp_timer_base = TIMERS_VIRT_BASE;
/*
- * FIXME: the timer needs some delay to stablize the counter capture
+ * Read the timer through the CVWR register. Delay is required after requesting
+ * a read. The CR register cannot be directly read due to metastability issues
+ * documented in the PXA168 software manual.
*/
static inline uint32_t timer_read(void)
{
- int delay = 100;
+ uint32_t val;
+ int delay = 3;
__raw_writel(1, mmp_timer_base + TMR_CVWR(1));
while (delay--)
- cpu_relax();
+ val = __raw_readl(mmp_timer_base + TMR_CVWR(1));
- return __raw_readl(mmp_timer_base + TMR_CVWR(1));
+ return val;
}
static u64 notrace mmp_read_sched_clock(void)