diff --git a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
index 4d01c1dd7f..b954de8101 100644
--- a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
+++ b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
@@ -2376,8 +2376,7 @@ AhciModeInitialization (
       AhciOrReg (PciIo, Offset, EFI_AHCI_PORT_CMD_FRE);
 
       //
-      // Wait no longer than 10 ms to wait the Phy to detect the presence of a device.
-      // It's the requirment from SATA1.0a spec section 5.2.
+      // Wait for the Phy to detect the presence of a device.
       //
       PhyDetectDelay = EFI_AHCI_BUS_PHY_DETECT_TIMEOUT;
       Offset = EFI_AHCI_PORT_START + Port * EFI_AHCI_PORT_REG_WIDTH + EFI_AHCI_PORT_SSTS;
diff --git a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.h b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.h
index 6401fb2e9f..809bcc307f 100644
--- a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.h
+++ b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.h
@@ -41,8 +41,9 @@ typedef union {
 
 //
 // Refer SATA1.0a spec section 5.2, the Phy detection time should be less than 10ms.
+// Add a bit of margin for robustness.
 //
-#define  EFI_AHCI_BUS_PHY_DETECT_TIMEOUT       10
+#define  EFI_AHCI_BUS_PHY_DETECT_TIMEOUT       15
 //
 // Refer SATA1.0a spec, the FIS enable time should be less than 500ms.
 //