From: Andrew Cooper <andrew.cooper3@citrix.com>
Date: Wed, 26 Feb 2014 16:21:22 +0000 (+0100)
Subject: x86/time: Remove redundant RTC REG_B read
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~5544
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=565d6a734a440219f371c890af1b624081b6f54f;p=xen.git

x86/time: Remove redundant RTC REG_B read

RTC_ALWAYS_BCD is always defined by default, meaning that we will
unconditionally enter the if statement.  Reordering the condition allows
short-circult evaluation to remove a redundant CMOS read.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c
index 6e31e1faed..82492c1784 100644
--- a/xen/arch/x86/time.c
+++ b/xen/arch/x86/time.c
@@ -661,7 +661,7 @@ static unsigned long __get_cmos_time(void)
     mon  = CMOS_READ(RTC_MONTH);
     year = CMOS_READ(RTC_YEAR);
     
-    if ( !(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD )
+    if ( RTC_ALWAYS_BCD || !(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) )
     {
         BCD_TO_BIN(sec);
         BCD_TO_BIN(min);