Re: [edk2-devel] [PATCH 1/1] MdeModulePkg/BdsDxe: Also call PlatformBootManagerWaitCallback on 0

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

On 09/25/19 17:50, Pete Batard wrote:
> The existing loop is set to call PlatformBootManagerWaitCallback every
> second except the last one. We believe this is a mistake as it prevents
> the called code from performing timeout expiration tasks such as, for
> instance, ensuring that the last segment of a progress bar is displayed
> before continuing (which is a current issue for the RPi3 platform).
> 
> Signed-off-by: Pete Batard <pete@akeo.ie>
> ---
>  MdeModulePkg/Universal/BdsDxe/BdsEntry.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/MdeModulePkg/Universal/BdsDxe/BdsEntry.c b/MdeModulePkg/Universal/BdsDxe/BdsEntry.c
> index f3d5e5ac0615..7968a58f3454 100644
> --- a/MdeModulePkg/Universal/BdsDxe/BdsEntry.c
> +++ b/MdeModulePkg/Universal/BdsDxe/BdsEntry.c
> @@ -341,6 +341,7 @@ BdsWait (
>        TimeoutRemain--;
>      }
>    }
> +  PlatformBootManagerWaitCallback (0);
>    DEBUG ((EFI_D_INFO, "[Bds]Exit the waiting!\n"));
>  }
>  
> 

I can confirm the problem statement, from a quick test with OVMF.

Regarding the PlatformBootManagerWaitCallback (0) call, it promises to
do the right thing, considering the following library instances:

- ArmVirtPkg/Library/PlatformBootManagerLib/PlatformBm.c
- OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c

In both cases, the function goes,

VOID
EFIAPI
PlatformBootManagerWaitCallback (
  UINT16          TimeoutRemain
  )
{
  EFI_GRAPHICS_OUTPUT_BLT_PIXEL_UNION Black;
  EFI_GRAPHICS_OUTPUT_BLT_PIXEL_UNION White;
  UINT16                              Timeout;

  Timeout = PcdGet16 (PcdPlatformBootTimeOut);

  Black.Raw = 0x00000000;
  White.Raw = 0x00FFFFFF;

  BootLogoUpdateProgress (
    White.Pixel,
    Black.Pixel,
    L"Start boot option",
    White.Pixel,
    (Timeout - TimeoutRemain) * 100 / Timeout,
    0
    );
}

If we substitute 0 for TimeoutRemain in the BootLogoUpdateProgress()
call, we get (Timeout * 100 / Timeout), i.e. 100%.

I haven't tested the patch, and I can't review it quickly for real, but
it looks plausible to me.

Thanks
Laszlo