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[Xen-changelog] [xen master] x86/time: Remove redundant RTC REG_B read



commit 565d6a734a440219f371c890af1b624081b6f54f
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Wed Feb 26 17:21:22 2014 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Feb 26 17:21:22 2014 +0100

    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@xxxxxxxxxx>
---
 xen/arch/x86/time.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c
index 6e31e1f..82492c1 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);
--
generated by git-patchbot for /home/xen/git/xen.git#master

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