From 5df0877aff76755db480d4b25712bb2bef508434 Mon Sep 17 00:00:00 2001 From: li-elvin Date: Mon, 27 Aug 2012 08:20:27 +0000 Subject: [PATCH] Add comments to explain the reason return status is not checked. The return status of KeyboardRead is not used. Signed-off-by: Li Elvin Reviewed-by: Yao Jiewen git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13679 6f19259b-4bc3-4df7-8a09-765794883524 --- .../Bus/Isa/Ps2KeyboardDxe/Ps2Keyboard.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/IntelFrameworkModulePkg/Bus/Isa/Ps2KeyboardDxe/Ps2Keyboard.c b/IntelFrameworkModulePkg/Bus/Isa/Ps2KeyboardDxe/Ps2Keyboard.c index 0b4aff7790..c73cf93613 100644 --- a/IntelFrameworkModulePkg/Bus/Isa/Ps2KeyboardDxe/Ps2Keyboard.c +++ b/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)) { -- 2.39.2