Re: [edk2-platforms][PATCH 1/1] Platform/RaspberryPi: Revert don't connect all devices on an ordinary boot

["Ard Biesheuvel" <ard.biesheuvel@arm.com>]

On 6/8/20 7:01 PM, Pete Batard wrote:
> On 2020.06.08 17:43, Ard Biesheuvel wrote:
>> On 6/8/20 5:51 PM, Pete Batard wrote:
>>> This reverts commit c8000ecccc83b728baf04ced2fedb870bc3bc1b3 on account
>>> of USB keyboard devices not being detected until after the timeout to
>>> enter the Setup menu or run the UEFI Shell has expired.
>>>
>>> The core of the issue is that, when EfiBootManagerConnectAll() is not
>>> invoked, PCI bus scanning only starts after the BDS wait period has
>>> elapsed, which effectively takes away the ability to use an USB device
>>> to enact Boot Device Selection or interact with the Setup menu.
>>>
>>> Signed-off-by: Pete Batard <pete@akeo.ie>
>>
>> Could we move the call to
>>
>> EfiEventGroupSignal (&gEfiEndOfDxeEventGroupGuid);
>>
>> to the start of PlatformBootManagerBeforeConsole() instead?
> 
> Moving EfiEventGroupSignal(&gEfiEndOfDxeEventGroupGuid) early into 
> PlatformBootManagerBeforeConsole() doesn't seem to have any effect, as 
> far as I could test.
> 
> We can however move the EfiBootManagerConnectAll() there if that's what 
> you are asking.
> 

No, the whole idea was to get rid of EfiBootManagerConnectAll().

You are saying the PCI bus scanning starts after the BDS wait period, 
right? This is strange, I wouldn't expect that. That is why I suggested 
moving the EfiEventGroupSignal() call earlier.

Looking at the ArmPkg version, it appears we need a sequence like

EfiEventGroupSignal (&gEfiEndOfDxeEventGroupGuid);

EfiBootManagerDispatchDeferredImages ();

FilterAndProcess (&gEfiPciRootBridgeIoProtocolGuid, NULL, Connect);

and that last call is missing from the RPi4 implementation.

After those calls, all the PCI I/O handles should be enumerated.


> 
>>
>>
>>
>>
>>> ---
>>>   Platform/RaspberryPi/Library/PlatformBootManagerLib/PlatformBm.c | 
>>> 5 +++++
>>>   1 file changed, 5 insertions(+)
>>>
>>> diff --git 
>>> a/Platform/RaspberryPi/Library/PlatformBootManagerLib/PlatformBm.c 
>>> b/Platform/RaspberryPi/Library/PlatformBootManagerLib/PlatformBm.c
>>> index 253614a646c1..2bd625ad7e7c 100644
>>> --- a/Platform/RaspberryPi/Library/PlatformBootManagerLib/PlatformBm.c
>>> +++ b/Platform/RaspberryPi/Library/PlatformBootManagerLib/PlatformBm.c
>>> @@ -655,6 +655,11 @@ PlatformBootManagerAfterConsole (
>>>       Print (BOOT_PROMPT);
>>>     }
>>> +  //
>>> +  // Connect the rest of the devices.
>>> +  //
>>> +  EfiBootManagerConnectAll ();
>>> +
>>>     Status = gBS->LocateProtocol (&gEsrtManagementProtocolGuid, NULL, 
>>> (VOID**)&EsrtManagement);
>>>     if (!EFI_ERROR (Status)) {
>>>       EsrtManagement->SyncEsrtFmp ();
>>>
>>
>