[Patch 1/3] NetworkPkg/UefiPxeBcDxe: Fix Pxe.Dhcp() return status code.

[Jiaxin Wu <jiaxin.wu@intel.com>]

According UEFI Spec, if valid PXE offer is not received, Pxe.Dhcp()
should return EFI_NO_RESPONSE, but currently, EFI_TIMEOUT is returned
from Pxe.Dhcp().

This patch is to fix the above issue.

Cc: Ye Ting <ting.ye@intel.com>
Cc: Fu Siyuan <siyuan.fu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Wu Jiaxin <jiaxin.wu@intel.com>
---
 NetworkPkg/UefiPxeBcDxe/PxeBcBoot.c  | 2 +-
 NetworkPkg/UefiPxeBcDxe/PxeBcDhcp4.c | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/NetworkPkg/UefiPxeBcDxe/PxeBcBoot.c b/NetworkPkg/UefiPxeBcDxe/PxeBcBoot.c
index fc50a82..0bb1d66 100644
--- a/NetworkPkg/UefiPxeBcDxe/PxeBcBoot.c
+++ b/NetworkPkg/UefiPxeBcDxe/PxeBcBoot.c
@@ -1240,11 +1240,11 @@ ON_EXIT:
   } else if (Status == EFI_OUT_OF_RESOURCES) {
     AsciiPrint ("\n  PXE-E09: Could not allocate I/O buffers.\n");
   } else if (Status == EFI_NO_MEDIA) {
     AsciiPrint ("\n  PXE-E12: Could not detect network connection.\n");
   } else if (Status == EFI_NO_RESPONSE) {
-    AsciiPrint ("\n  PXE-E16: No offer received.\n");
+    AsciiPrint ("\n  PXE-E16: No valid offer received.\n");
   } else if (Status == EFI_TIMEOUT) {
     AsciiPrint ("\n  PXE-E18: Server response timeout.\n");
   } else if (Status == EFI_ABORTED) {
     AsciiPrint ("\n  PXE-E21: Remote boot cancelled.\n");
   } else if (Status == EFI_ICMP_ERROR) {
diff --git a/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp4.c b/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp4.c
index 97829e9..101c658 100644
--- a/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp4.c
+++ b/NetworkPkg/UefiPxeBcDxe/PxeBcDhcp4.c
@@ -1705,10 +1705,15 @@ PxeBcDhcp4Dora (
   Status = Dhcp4->Start (Dhcp4, NULL);
   if (EFI_ERROR (Status) && Status != EFI_ALREADY_STARTED) {
     if (Status == EFI_ICMP_ERROR) {
       PxeMode->IcmpErrorReceived = TRUE;
     }
+
+    if (Status == EFI_TIMEOUT && Private->OfferNum > 0) {
+      Status = EFI_NO_RESPONSE;
+    }
+    
     goto ON_EXIT;
   }
 
   //
   // Get the acquired IPv4 address and store them.
-- 
1.9.5.msysgit.1