MdeModulePkg/Ata: Clear PxCmd.SUD bit when the port has no device presented at AHCI...

Signed-off-by: Feng Tian <feng.tian@intel.com>
Reviewed-by: Sun Rui <rui.sun@intel.com>
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13370 6f19259b-4bc3-4df7-8a09-765794883524

diff --git a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
index 42ee5bc58091cdffc852c6fe99011cfbd1197f96..c2c2c2869a391a33e7e2c9ca3903fd0023c48772 100644 (file)
--- a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
+++ b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
@@ -2278,7 +2278,10 @@ AhciModeInitialization (
       if (PhyDetectDelay == 0) {\r
         //\r
         // No device detected at this port.\r
+        // Clear PxCMD.SUD for those ports at which there are no device present.\r
         //\r
+        Offset = EFI_AHCI_PORT_START + Port * EFI_AHCI_PORT_REG_WIDTH + EFI_AHCI_PORT_CMD;\r
+        AhciAndReg (PciIo, Offset, (UINT32) ~(EFI_AHCI_PORT_CMD_SUD));\r
         continue;\r
       }\r
 \r