Maybe you are right. I would try to figure out the issue in graphics console 
devices.
Making edk2 do not unnecessarily re-initialize is a good idea. But the ‘flicker 
free’ is depend on the platform code designer. By default the flicker would 
always happen because of some pcds 
(gEfiMdeModulePkgTokenSpaceGuid.PcdVideoHorizontalResolution, 
gEfiMdeModulePkgTokenSpaceGuid.PcdVideoVerticalResolution). The two pcds have 
default value, we suggest the platform to set them to zero in the platform dsc 
file and that means the platform would initialize the screen resolution to the 
maximum. If not and the screen’s resolution is different with the default 
value, then the screen would flicker and set the screen to the default 
resolution.
For now, I didn’t find other issues in edk2 code.

Thanks,
Zhichao

From: sean.brogan via groups.io [mailto:[email protected]]
Sent: Tuesday, April 30, 2019 9:08 AM
To: Gao; Gao, Zhichao <[email protected]>; [email protected]
Subject: Re: [edk2-devel] [PATCH V2 2/2] MdeModulePkg/GraphicsConsoleDxe: Do 
not clean the screen

Zhichao,

That sounds like a bug in you graphics console devices.  If they are already 
initialized (by pei or other platform code) they should not start in mode -1.
For bug 1412, can we make sure all Tianocore edk2 drivers support "flicker 
free" and don't unncecessarly re-initialize.  Do you see other issues in edk2 
code?

Thanks
Sean

-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.

View/Reply Online (#39831): https://edk2.groups.io/g/devel/message/39831
Mute This Topic: https://groups.io/mt/31306535/21656
Group Owner: [email protected]
Unsubscribe: https://edk2.groups.io/g/devel/unsub  [[email protected]]
-=-=-=-=-=-=-=-=-=-=-=-

Reply via email to