MdeModulePkg/EhciDxe: Fix legacy handoff logic

references acidanthera/bugtracker#2436
acidanthera · Oct 27, 2024 · 0130690 · 0130690
1 parent 431595f
commit 0130690
Showing 1 changed file with 11 additions and 0 deletions.
diff --git a/MdeModulePkg/Bus/Pci/EhciDxe/EhciReg.c b/MdeModulePkg/Bus/Pci/EhciDxe/EhciReg.c
@@ -309,6 +309,17 @@ EhcClearLegacySupport (
   PciIo->Pci.Read (PciIo, EfiPciIoWidthUint32, ExtendCap, 1, &Value);
   PciIo->Pci.Read (PciIo, EfiPciIoWidthUint32, ExtendCap + 0x4, 1, &Value);
 
+  //
+  // Disable the SMI in USBLEGCTLSTS firstly
+  // Not doing this may result in a hardlock soon after
+  //
+  PciIo->Pci.Read (PciIo, EfiPciIoWidthUint32, ExtendCap + 0x4, 1, &Value);
+  Value &= 0xFFFF0000;
+  PciIo->Pci.Write (PciIo, EfiPciIoWidthUint32, ExtendCap + 0x4, 1, &Value);
+
+  //
+  // Get EHCI Ownership from legacy bios
+  //
   PciIo->Pci.Read (PciIo, EfiPciIoWidthUint32, ExtendCap, 1, &Value);
   Value |= (0x1 << 24);
   PciIo->Pci.Write (PciIo, EfiPciIoWidthUint32, ExtendCap, 1, &Value);