Re: [edk2-devel] [PATCH 1/1] MdeModulePkg/XhciDxe: Fix Broken Timeouts

["Laszlo Ersek" <lersek@redhat.com>]

Hi Patrick,

On 09/01/20 20:55, patrick.henz@hpe.com wrote:
> From: henz <patrick.henz@hpe.com>

some meta-comments:

(1) Please consider setting the "user.name" item in your git config to
your full name, "Patrick Henz". Because right now it seems to be just
"henz", and that doesn't look very nice in the git commit history.

(2) When you update this patch for v2, point (1) will not fix this very
patch however. So please update this particular patch with

  git commit --amend --author='Patrick Henz <patrick.henz@hpe.com>'

(3) Please run

  python3 BaseTools/Scripts/SetupGit.py

in your edk2 clone -- it automates a bunch of the settings listed at
<https://github.com/tianocore/tianocore.github.io/wiki/Laszlo%27s-unkempt-git-guide-for-edk2-contributors-and-maintainers#contrib-05>,
and more. For example, it sets 8bit content-transfer-encoding for
mailing out your edk2 patches, which is helpful because quoted-printable
doesn't play nice with the hard CRLF line endings that edk2 uses.

Thank you!
Laszlo


> 
> 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   | 28 ++++++++++++++++---
>  MdeModulePkg/Bus/Pci/XhciDxe/XhciSched.c | 34 +++++++++++++++++-------
>  2 files changed, 49 insertions(+), 13 deletions(-)
> 
> diff --git a/MdeModulePkg/Bus/Pci/XhciDxe/XhciReg.c b/MdeModulePkg/Bus/Pci/XhciDxe/XhciReg.c
> index 42b773ab31..5f7507f0a5 100644
> --- a/MdeModulePkg/Bus/Pci/XhciDxe/XhciReg.c
> +++ b/MdeModulePkg/Bus/Pci/XhciDxe/XhciReg.c
> @@ -442,17 +442,37 @@ XhcWaitOpRegBit (
>    IN UINT32               Timeout
> 
>    )
> 
>  {
> 
> -  UINT32                  Index;
> 
> -  UINT64                  Loop;
> 
> +  EFI_STATUS Status;
> 
> +  EFI_EVENT  TimeoutEvent;
> 
>  
> 
> -  Loop   = Timeout * XHC_1_MILLISECOND;
> 
> +  if (Timeout == 0) {
> 
> +    return EFI_TIMEOUT;
> 
> +  }
> 
> +
> 
> +  Status = gBS->CreateEvent (
> 
> +                  EVT_TIMER,
> 
> +                  TPL_CALLBACK,
> 
> +                  NULL,
> 
> +                  NULL,
> 
> +                  &TimeoutEvent
> 
> +                  );
> 
>  
> 
> -  for (Index = 0; Index < Loop; Index++) {
> 
> +  if (!EFI_ERROR (Status)) {
> 
> +    Status = gBS->SetTimer (TimeoutEvent,
> 
> +                            TimerRelative,
> 
> +                            EFI_TIMER_PERIOD_MILLISECONDS(Timeout));
> 
> +  }
> 
> +
> 
> +  do {
> 
>      if (XHC_REG_BIT_IS_SET (Xhc, Offset, Bit) == WaitToSet) {
> 
>        return EFI_SUCCESS;
> 
>      }
> 
>  
> 
>      gBS->Stall (XHC_1_MICROSECOND);
> 
> +  } while (!EFI_ERROR(Status) && EFI_ERROR(gBS->CheckEvent (TimeoutEvent)));
> 
> +
> 
> +  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 ab8957c546..cf271f0493 100644
> --- a/MdeModulePkg/Bus/Pci/XhciDxe/XhciSched.c
> +++ b/MdeModulePkg/Bus/Pci/XhciDxe/XhciSched.c
> @@ -1273,11 +1273,11 @@ XhcExecTransfer (
>    )
> 
>  {
> 
>    EFI_STATUS              Status;
> 
> -  UINTN                   Index;
> 
> -  UINT64                  Loop;
> 
>    UINT8                   SlotId;
> 
>    UINT8                   Dci;
> 
>    BOOLEAN                 Finished;
> 
> +  EFI_EVENT               TimeoutEvent;
> 
> +  EFI_STATUS              TimerStatus;
> 
>  
> 
>    if (CmdTransfer) {
> 
>      SlotId = 0;
> 
> @@ -1292,28 +1292,44 @@ XhcExecTransfer (
>    }
> 
>  
> 
>    Status = EFI_SUCCESS;
> 
> -  Loop   = Timeout * XHC_1_MILLISECOND;
> 
> -  if (Timeout == 0) {
> 
> -    Loop = 0xFFFFFFFF;
> 
> -  }
> 
> +
> 
> +  TimerStatus = gBS->CreateEvent (
> 
> +                       EVT_TIMER,
> 
> +                       TPL_CALLBACK,
> 
> +                       NULL,
> 
> +                       NULL,
> 
> +                       &TimeoutEvent
> 
> +                       );
> 
>  
> 
>    XhcRingDoorBell (Xhc, SlotId, Dci);
> 
>  
> 
> -  for (Index = 0; Index < Loop; Index++) {
> 
> +  if (!EFI_ERROR (TimerStatus)) {
> 
> +    TimerStatus = gBS->SetTimer (TimeoutEvent,
> 
> +                                 TimerRelative,
> 
> +                                 (0 == Timeout)?
> 
> +                                 (EFI_TIMER_PERIOD_MICROSECONDS(0xFFFFFFFF)):
> 
> +                                 (EFI_TIMER_PERIOD_MILLISECONDS(Timeout)));
> 
> +  }
> 
> +
> 
> +  do {
> 
>      Finished = XhcCheckUrbResult (Xhc, Urb);
> 
>      if (Finished) {
> 
>        break;
> 
>      }
> 
>      gBS->Stall (XHC_1_MICROSECOND);
> 
> -  }
> 
> +  } while (!EFI_ERROR(TimerStatus) && EFI_ERROR(gBS->CheckEvent (TimeoutEvent)));
> 
>  
> 
> -  if (Index == Loop) {
> 
> +  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;
> 
>  }
> 
>  
>