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authorli-elvin <li-elvin@6f19259b-4bc3-4df7-8a09-765794883524>2012-08-27 08:20:27 +0000
committerli-elvin <li-elvin@6f19259b-4bc3-4df7-8a09-765794883524>2012-08-27 08:20:27 +0000
commitf3d04717064f3e523c6a841f0769d198b0a5e907 (patch)
tree5417ec879ea9fabdda3dbf7e7b0c2a032696edf6
parent9477e0b4e8f545d58c981a0e2a459c638eb02714 (diff)
Add comments to explain the reason return status is not checked. The return status of KeyboardRead is not used.
Signed-off-by: Li Elvin <elvin.li@intel.com> Reviewed-by: Yao Jiewen <jiewen.yao@intel.com> git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk@13679 6f19259b-4bc3-4df7-8a09-765794883524
-rw-r--r--edk2/IntelFrameworkModulePkg/Bus/Isa/Ps2KeyboardDxe/Ps2Keyboard.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/edk2/IntelFrameworkModulePkg/Bus/Isa/Ps2KeyboardDxe/Ps2Keyboard.c b/edk2/IntelFrameworkModulePkg/Bus/Isa/Ps2KeyboardDxe/Ps2Keyboard.c
index 0b4aff779..c73cf9361 100644
--- a/edk2/IntelFrameworkModulePkg/Bus/Isa/Ps2KeyboardDxe/Ps2Keyboard.c
+++ b/edk2/IntelFrameworkModulePkg/Bus/Isa/Ps2KeyboardDxe/Ps2Keyboard.c
@@ -255,6 +255,13 @@ KbdControllerDriverStart (
//
// Fix for random hangs in System waiting for the Key if no KBC is present in BIOS.
+ // When KBC decode (IO port 0x60/0x64 decode) is not enabled,
+ // KeyboardRead will read back as 0xFF and return status is EFI_SUCCESS.
+ // So instead we read status register to detect after read if KBC decode is enabled.
+ //
+
+ //
+ // Return code is ignored on purpose.
//
KeyboardRead (ConsoleIn, &Data);
if ((KeyReadStatusRegister (ConsoleIn) & (KBC_PARE | KBC_TIM)) == (KBC_PARE | KBC_TIM)) {