[PATCH v2 1/1] MdeModulePkg/XhciDxe: Fix Broken Timeouts

[patrick.henz@hpe.com]

From: Patrick Henz <patrick.henz@hpe.com>

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2948

Timeouts in the XhciDxe driver are taking longer than
expected due to the timeout loops not accounting for
code execution time. As en example, 5 second timeouts
have been observed to take around 36 seconds to complete.
Use SetTimer and Create/CheckEvent from Boot Services to
determine when timeout occurred.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Signed-off-by: Patrick Henz <patrick.henz@hpe.com>
---
 MdeModulePkg/Bus/Pci/XhciDxe/XhciReg.c   | 35 ++++++++++++++++---
 MdeModulePkg/Bus/Pci/XhciDxe/XhciSched.c | 43 +++++++++++++++++++-----
 2 files changed, 65 insertions(+), 13 deletions(-)

diff --git a/MdeModulePkg/Bus/Pci/XhciDxe/XhciReg.c b/MdeModulePkg/Bus/Pci/XhciDxe/XhciReg.c
index 42b773ab31be..33ac13504669 100644
--- a/MdeModulePkg/Bus/Pci/XhciDxe/XhciReg.c
+++ b/MdeModulePkg/Bus/Pci/XhciDxe/XhciReg.c
@@ -442,17 +442,44 @@ XhcWaitOpRegBit (
   IN UINT32               Timeout
   )
 {
-  UINT32                  Index;
-  UINT64                  Loop;
+  EFI_STATUS Status;
+  EFI_EVENT  TimeoutEvent;
 
-  Loop   = Timeout * XHC_1_MILLISECOND;
+  TimeoutEvent = NULL;
 
-  for (Index = 0; Index < Loop; Index++) {
+  if (Timeout == 0) {
+    goto TIMEOUT;
+  }
+
+  Status = gBS->CreateEvent (
+                  EVT_TIMER,
+                  TPL_CALLBACK,
+                  NULL,
+                  NULL,
+                  &TimeoutEvent
+                  );
+
+  if (!EFI_ERROR (Status)) {
+    Status = gBS->SetTimer (TimeoutEvent,
+                            TimerRelative,
+                            EFI_TIMER_PERIOD_MILLISECONDS(Timeout));
+  }
+
+  if (EFI_ERROR(Status)) {
+    goto TIMEOUT;
+  }
+
+  do {
     if (XHC_REG_BIT_IS_SET (Xhc, Offset, Bit) == WaitToSet) {
       return EFI_SUCCESS;
     }
 
     gBS->Stall (XHC_1_MICROSECOND);
+  } while (EFI_ERROR(gBS->CheckEvent (TimeoutEvent)));
+
+TIMEOUT:
+  if (TimeoutEvent != NULL) {
+    gBS->CloseEvent (TimeoutEvent);
   }
 
   return EFI_TIMEOUT;
diff --git a/MdeModulePkg/Bus/Pci/XhciDxe/XhciSched.c b/MdeModulePkg/Bus/Pci/XhciDxe/XhciSched.c
index ab8957c546ee..d6290b5fe33b 100644
--- a/MdeModulePkg/Bus/Pci/XhciDxe/XhciSched.c
+++ b/MdeModulePkg/Bus/Pci/XhciDxe/XhciSched.c
@@ -1273,11 +1273,19 @@ XhcExecTransfer (
   )
 {
   EFI_STATUS              Status;
-  UINTN                   Index;
-  UINT64                  Loop;
   UINT8                   SlotId;
   UINT8                   Dci;
   BOOLEAN                 Finished;
+  EFI_EVENT               TimeoutEvent;
+  EFI_STATUS              TimerStatus;
+
+  Status       = EFI_SUCCESS;
+  Finished     = FALSE;
+  TimeoutEvent = NULL;
+
+  if (Timeout == 0) {
+    goto DONE;
+  }
 
   if (CmdTransfer) {
     SlotId = 0;
@@ -1291,29 +1299,46 @@ XhcExecTransfer (
     ASSERT (Dci < 32);
   }
 
-  Status = EFI_SUCCESS;
-  Loop   = Timeout * XHC_1_MILLISECOND;
-  if (Timeout == 0) {
-    Loop = 0xFFFFFFFF;
+  TimerStatus = gBS->CreateEvent (
+                       EVT_TIMER,
+                       TPL_CALLBACK,
+                       NULL,
+                       NULL,
+                       &TimeoutEvent
+                       );
+
+  if (!EFI_ERROR (TimerStatus)) {
+    TimerStatus = gBS->SetTimer (TimeoutEvent,
+                                 TimerRelative,
+                                 EFI_TIMER_PERIOD_MILLISECONDS(Timeout));
+  }
+
+  if (EFI_ERROR (TimerStatus)) {
+    goto DONE;
   }
 
   XhcRingDoorBell (Xhc, SlotId, Dci);
 
-  for (Index = 0; Index < Loop; Index++) {
+  do {
     Finished = XhcCheckUrbResult (Xhc, Urb);
     if (Finished) {
       break;
     }
     gBS->Stall (XHC_1_MICROSECOND);
-  }
+  } while (EFI_ERROR(gBS->CheckEvent (TimeoutEvent)));
 
-  if (Index == Loop) {
+DONE:
+  if (!Finished) {
     Urb->Result = EFI_USB_ERR_TIMEOUT;
     Status      = EFI_TIMEOUT;
   } else if (Urb->Result != EFI_USB_NOERROR) {
     Status      = EFI_DEVICE_ERROR;
   }
 
+  if (TimeoutEvent != NULL) {
+    gBS->CloseEvent (TimeoutEvent);
+  }
+
   return Status;
 }
 
-- 
2.28.0