chiujyh
Posts: 2
Joined: Tue Jun 22, 2021 2:48 am

PRi 4B+ DPI HDMI display at the same time?

Tue Jun 22, 2021 4:05 am

I have a project . It need two display . One is connect to the monitor , The other that designed convert from DPI (GPIO) is fixed 1026x600 display. For DPI output ,we fix the /boot/config.txt in the following setting on the Raspberry PI OS(2021), But HDMI can't display .
Can help to solve the display at the same time . TKS.
//-----------------------------------------------------------------------------------------------------------
[pi4]
# Enable DRM VC4 V3D driver on top of the dispmanx display stack
#dtoverlay=vc4-fkms-v3d
max_framebuffers=2
dpi_timings=1024 1 96 30 126 600 0 12 12 12 0 0 0 60 0 48700000 6

[all]
#dtoverlay=vc4-fkms-v3d
dtoverlay=dpi24
enable_dpi_lcd=1
display_default_lcd=1
dpi_group=2
dpi_mode=87
dpi_output_format=0x6f007
hdmi_cvt 1024 600 60 6 0 0 0
disable_overscan=1
//------------------------------------------------------------------------------------------------------

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 29018
Joined: Sat Jul 30, 2011 7:41 pm

Re: PRi 4B+ DPI HDMI display at the same time?

Tue Jun 22, 2021 9:25 am

What does

Code: Select all

tvservice --list
return?
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Working in the Application's Team.

aBUGSworstnightmare
Posts: 3203
Joined: Tue Jun 30, 2015 1:35 pm

Re: PRi 4B+ DPI HDMI display at the same time?

Tue Jun 22, 2021 6:49 pm

You really want to use legacy driver for this, or why did you disable FKMS?

What is the intention of this command 'hdmi_cvt 1024 600 60 6'? Is it your monitor? Doesn't it provide EDID?

chiujyh
Posts: 2
Joined: Tue Jun 22, 2021 2:48 am

Re: PRi 4B+ DPI HDMI display at the same time?

Thu Jun 24, 2021 6:43 am

If I add the " dtoverlay=vc4-fkms-v3d" , the DPI output will stop .
The project need two screen one is HDMI , the other is DPI output monitor ,
The Waveshare LCD TFT DPI monitor wiki suggest setup this .
It do close the vc4-fkms -v3d driver . and the DPI output OK , But HDMI is close

Is there some good idea to solve the issue ?
TKS.

aBUGSworstnightmare
Posts: 3203
Joined: Tue Jun 30, 2015 1:35 pm

Re: PRi 4B+ DPI HDMI display at the same time?

Thu Jun 24, 2021 8:46 am

chiujyh wrote:Is there some good idea to solve the issue ?
TKS.
start with telling full details of what HW you're using and what is in your config.txt....

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