Raise TPL to prevent the BlockIo instance for USB device is removed during the locating the instance and using it.

Signed-off-by: niruiyu
Reviewed-by: erictian

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12203 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 11 insertions, 0 deletions

diff --git a/IntelFrameworkModulePkg/Library/GenericBdsLib/BdsBoot.c b/IntelFrameworkModulePkg/Library/GenericBdsLib/BdsBoot.c
index 1ac2946360..a697fcfda3 100644
--- a/IntelFrameworkModulePkg/Library/GenericBdsLib/BdsBoot.c
+++ b/IntelFrameworkModulePkg/Library/GenericBdsLib/BdsBoot.c
@@ -1904,6 +1904,7 @@ BdsLibGetBootableHandle (
   )

 {

   EFI_STATUS                      Status;

+  EFI_TPL                         OldTpl;

   EFI_DEVICE_PATH_PROTOCOL        *UpdatedDevicePath;

   EFI_DEVICE_PATH_PROTOCOL        *DupDevicePath;

   EFI_HANDLE                      Handle;

@@ -1924,6 +1925,12 @@ BdsLibGetBootableHandle (
   UpdatedDevicePath = DevicePath;

 

   //

+  // Enter to critical section to protect the acquired BlockIo instance 

+  // from getting released due to the USB mass storage hotplug event

+  //

+  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);

+

+  //

   // Check whether the device is connected

   //

   Status = gBS->LocateDevicePath (&gEfiBlockIoProtocolGuid, &UpdatedDevicePath, &Handle);

@@ -1950,6 +1957,8 @@ BdsLibGetBootableHandle (
     // Get BlockIo protocol and check removable attribute

     //

     Status = gBS->HandleProtocol (Handle, &gEfiBlockIoProtocolGuid, (VOID **)&BlockIo);

+    ASSERT_EFI_ERROR (Status);

+

     //

     // Issue a dummy read to the device to check for media change.

     // When the removable media is changed, any Block IO read/write will

@@ -2046,6 +2055,8 @@ BdsLibGetBootableHandle (
     FreePool(SimpleFileSystemHandles);

   }

 

+  gBS->RestoreTPL (OldTpl);

+

   return ReturnHandle;

 }