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Date: Thu, 19 Jan 2012 17:22:22 +0530 From: Venu Byravarasu <vbyravarasu@...dia.com> To: a.zummo@...ertech.it, rtc-linux@...glegroups.com, linux-kernel@...r.kernel.org Cc: Venu Byravarasu <vbyravarasu@...dia.com> Subject: [PATCH] rtc: twl: optimize IRQ bit access From: Venu Byravarasu <vbyravarasu@...dia.com> As TWL RTC driver is having a cached copy of enabled RTC interrupt bits in variable rtc_irq_bits, that can be checked before really setting or masking any of the interrupt bits. Signed-off-by: Venu Byravarasu <vbyravarasu@...dia.com> --- drivers/rtc/rtc-twl.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-) diff --git a/drivers/rtc/rtc-twl.c b/drivers/rtc/rtc-twl.c index a0236a0..b1f6c8b 100644 --- a/drivers/rtc/rtc-twl.c +++ b/drivers/rtc/rtc-twl.c @@ -176,6 +176,10 @@ static int set_rtc_irq_bit(unsigned char bit) unsigned char val; int ret; + /* if the bit is set, return from here */ + if (rtc_irq_bits & bit) + return 0; + val = rtc_irq_bits | bit; val &= ~BIT_RTC_INTERRUPTS_REG_EVERY_M; ret = twl_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG); @@ -193,6 +197,10 @@ static int mask_rtc_irq_bit(unsigned char bit) unsigned char val; int ret; + /* if the bit is clear, return from here */ + if (!(rtc_irq_bits & bit)) + return 0; + val = rtc_irq_bits & ~bit; ret = twl_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG); if (ret == 0) -- 1.7.1.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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