Re: [edk2-devel] [PATCH v2 1/2] OvmfPkg/PlatformBootManagerLib: Don't update progress if Pcd is 0

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 10/14/19 5:03 PM, Pete Batard wrote:
> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2266
> 
> Independently of how we decide to address other aspects of the regression
> introduced with commit 2de1f611be06ded3a59726a4052a9039be7d459b, it doesn't
> make much sense to call for a progress update if PcdPlatformBootTimeOut is
> zero.
> 
> PcdPlatformBootTimeOut 0, which is the cause of the bug (division by zero)
> should be considered to indicate that a platform is not interested in
> displaying a progress report, so we alter PlatformBootManagerWaitCallback
> to behave that way.
> 
> We also change one variable name to make the code more explicit.
> 
> Signed-off-by: Pete Batard <pete@akeo.ie>

You can keep:
Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>

> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
> ---
>   OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c | 15 ++++++++++++---
>   1 file changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c b/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c
> index 70df6b841acc..8af9b71f18a3 100644
> --- a/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c
> +++ b/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c
> @@ -1631,9 +1631,18 @@ PlatformBootManagerWaitCallback (
>   {
>     EFI_GRAPHICS_OUTPUT_BLT_PIXEL_UNION Black;
>     EFI_GRAPHICS_OUTPUT_BLT_PIXEL_UNION White;
> -  UINT16                              Timeout;
> +  UINT16                              TimeoutInitial;
>   
> -  Timeout = PcdGet16 (PcdPlatformBootTimeOut);
> +  TimeoutInitial = PcdGet16 (PcdPlatformBootTimeOut);
> +
> +  //
> +  // If PcdPlatformBootTimeOut is set to zero, then we consider
> +  // that no progress update should be enacted (since we'd only
> +  // ever display a one-shot progress of either 0% or 100%).
> +  //
> +  if (TimeoutInitial == 0) {
> +    return;
> +  }
>   
>     Black.Raw = 0x00000000;
>     White.Raw = 0x00FFFFFF;
> @@ -1643,7 +1652,7 @@ PlatformBootManagerWaitCallback (
>       Black.Pixel,
>       L"Start boot option",
>       White.Pixel,
> -    (Timeout - TimeoutRemain) * 100 / Timeout,
> +    (TimeoutInitial - TimeoutRemain) * 100 / TimeoutInitial,
>       0
>       );
>   }
>