[Xen-changelog] [xen master] rombios/ata: Reading this status register has no relevant side effects

[patchbot@xxxxxxx]

commit db46adf193be09e33fb1778f840cda5de91c777e
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Tue Aug 6 14:48:38 2013 +0100
Commit:     Ian Campbell <ian.campbell@xxxxxxxxxx>
CommitDate: Thu Aug 8 12:03:16 2013 +0100

    rombios/ata: Reading this status register has no relevant side effects
    
    So taking two traps when one will do is pointless.  This removes 1 of 13
    VMExits on the int 0x13 hotpath.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Acked-by: Keir Fraser <keir@xxxxxxx>
---
 tools/firmware/rombios/rombios.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/tools/firmware/rombios/rombios.c b/tools/firmware/rombios/rombios.c
index a3efc61..f555747 100644
--- a/tools/firmware/rombios/rombios.c
+++ b/tools/firmware/rombios/rombios.c
@@ -2540,7 +2540,6 @@ static int await_ide(when_done,base,timeout)
   Bit32u time=0,last=0;
   Bit16u status;
   Bit8u result;
-  status = inb(base + ATA_CB_STAT); // for the times you're supposed to throw 
one away
   for(;;) {
     status = inb(base+ATA_CB_STAT);
     time++;
--
generated by git-patchbot for /home/xen/git/xen.git#master

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