The change you provided is covered in patch #1.

But that can only save one problem:

not to repeat clearing the screen which is already set a console mode while adding console devices.

This is not match the info in 1412: “This is not a desired behavior when booting a consumer device as it clears the boot logo.”

For the first time, the screens are always cleared because its initial mode is ‘-1’ which is regarding as an invalid mode.

Here is the code covered your change:

https://github.com/ZhichaoGao/edk2/commit/72d5198cb131c456eb250b88a8bd7e6cf2d18b3b

And the blow is the change which can solve the clear screen issue, and this is incorrect based on the discussion in the community:

https://github.com/ZhichaoGao/edk2/commit/8ed0248c74564e2d8be0babca1ef0b49e4147478

If I have any mistakes, please correct them.

Thanks,

Zhichao

From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of Sean via Groups.Io
Sent: Friday, April 26, 2019 9:12 AM
To: Gao; Gao, Zhichao <zhichao.gao@intel.com>; devel@edk2.groups.io
Subject: Re: [edk2-devel] [PATCH V2 2/2] MdeModulePkg/GraphicsConsoleDxe: Do not clean the screen

Is there a branch where this code change can be reviewed?  

The intent of bug 1412 was not to break spec alignment on the uefi defined protocol and SetMode() function.  We had a proposed change that can be seen here. https://github.com/Microsoft/mu_basecore/pull/13/files
The idea was for new devices published, only clear the screen if the mode needs to change.  Our reading of the UEFI spec didn't define how new devices needed to be added and didn't require the screen be cleared.