Screen resolution issue

[marlab]

Hi marlab, if the Pi 4 Works please let me know..

Yes it actually works nicely

I had a spare RPi4 2MB RAM, so I thought I would just connect quickly for a test, but... it stays here. No more audio drops (I use external USB DAC), no more sluggish screen I had with RPi3... Do not get me wrong - RPi3 worked perfectly in the headless mode, until I've connected the external screen, which seems to require more horsepower.

I've managed to lower the resolution, as some controls are simply too small on my 7" screen. Just for the reference, that's what I currently have in /boot/firmware/config.txt. It can be possibly improved... but I still enjoy the fact it started working nicely, and I'll perfect it later:

Code:

# Device filters
[cm4]
otg_mode=1
[pi4]
hdmi_force_hotplug:0=0
hdmi_force_hotplug:1=0
hdmi_enable_4kp60=0
[all]
#dtoverlay=vc4-kms-v3d
max_framebuffers=1
#display_auto_detect=1
disable_fw_kms_setup=1
arm_64bit=1

# General settings
arm_boost=0
disable_splash=1
disable_overscan=1
hdmi_drive=2
hdmi_blanking=1
hdmi_force_edid_audio=1
hdmi_force_hotplug=1
#hdmi_group=0

hdmi_cvt=768 460 60 3 0 0 0
hdmi_group=2
hdmi_mode=87

[LostOne]

Hi Tim,
So I am guessing that it is turning to Firmware mode, as I have no DAC on the Pi yet?
because firmware mode would explain this, as the initial boot screen before drivers are loaded has the same display area and placement as the local display.
I thought it was reverting to something like that so I just need the DAC that is coming and a little testing.

Thanks for the help people.

Regards,
Neil

[DRONE7]

How refreshing to see 'reverting' used without the usual tautological addition of 'back'! (pet peeve I know)

[LostOne]

Putting a Pi DAC pro on the Pi made no difference to it reverting back to Firmware mode on the screen.

[LostOne]

so I purchased a Pi 4 B 4gb put a dac pro on it. and i still have exactly the same issue?

[Tim Curtis]

Hi Tim,
So I am guessing that it is turning to Firmware mode, as I have no DAC on the Pi yet?
because firmware mode would explain this, as the initial boot screen before drivers are loaded has the same display area and placement as the local display.
I thought it was reverting to something like that so I just need the DAC that is coming and a little testing.

Thanks for the help people.

Regards,
Neil

Couple things:

1. The setting that controls whether the Kernel or Firmware video driver mode is used is located on Audio Config screen
2. It only appears for Pi models that have a headphone jack. This means that it won't appear for Pi5
3. The mode has to be manually set by changing the setting. There is no automatic mode switch during startup
4. The setting is only for enabling the headphone jack. No other audio, video or system features are supported.