question

You missed one important step:

remove /etc/venus/headless

With that file present, the local GUI does display on the local screen and you only have the GUI via a web page.

ssh access is disabled by default so you will need the web-based GUI to enable it. Then ssh in from a computer on the same network.

You can also enable local console by replacing the only line in /u-boot/cmdline.txt with:

dwc_otg.lpm_enable=0 console=serial0,115200 console=tty0 logo.nologo

That should make the boot progress show on the display followed by a command line prompt.

Then you can use something like the AdaFruit serial console interface plugged onto the GPIO pins and a terminal emulator to enter commands.

So think have figured out the cause of issue based on below info from this post, and can confirm that v2.90 is now running "5.10.110-rpi-venus-4".

I have the same display, and have had the same issue. Works fine with a 4.x kernel, but the upgrade to 5.4 renders it useless. Just a white screen on boot.

It looks like pin 22 (GPIO6/BCM 25) isn't taken high on boot -- or rather, its taken high briefly.

By manually pulling this up to 3.3v the display works with the tft35a overlay found here: https://github.com/goodtft/LCD-show/raw/master/usr/tft35a-overlay.dtb

A 'fix' is to update the dtb to set 0x19 high when applying the overlay. The following /should/ apply the fix:

wget https://github.com/goodtft/LCD-show/raw/master/usr/tft35a-overlay.dtb -O tft35a-org.dtbo
dtc -I dtb -O dts -o tft35a-org.dts tft35a-org.dtbo
cat tft35a-org.dts | sed s/\<\ 0xdeadbeef\ 0x19\ 0x00\ \>/\<\ 0xdeadbeef\ 0x19\ 0x01\ \>/g > tft35b.dts
dtc -@ -I dts -O dtb -o /boot/overlays/tft35b.dtbo tft35b.dts
echo -e "hdmi_force_hotplug=1\ndtparam=spi=on\ndtoverlay=tft35b" >> /boot/config.txt
sed -i s/rootwait$/rootwait\ fbcon=map:1\ fbcon=font:ProFont6x11\ logo.nologo/g /boot/cmdline.txt

But I can't get it to run the below dtc cmd without getting errors. Anyone knowledgeable on topic and can help?

dtc -I dtb -O dts -o tft35a-org.dts tft35a-org.dtbo

tft35a-org.dts: Warning (unit_address_vs_reg): /fragment@0/__overlay__/spidev@0: node has a unit name, but no reg or ranges property

tft35a-org.dts: Warning (unit_address_vs_reg): /fragment@0/__overlay__/spidev@1: node has a unit name, but no reg or ranges property

tft35a-org.dts: Warning (gpios_property): /fragment@2/__overlay__/tft35a@0:reset-gpios: Could not get phandle node for (cell 0)

tft35a-org.dts: Warning (gpios_property): /fragment@2/__overlay__/tft35a@0:dc-gpios: Could not get phandle node for (cell 0)

tft35a-org.dts: Warning (gpios_property): /fragment@2/__overlay__/tft35a-ts@1:pendown-gpio: Could not get phandle node for (cell 0)

tft35a-org.dts: Warning (gpios_property): /__fixups__:gpio: property size (218) is invalid, expected multiple of 4

tft35a-org.dts: Warning (interrupts_property): /fragment@2/__overlay__/tft35a-ts@1:interrupt-parent: Bad phandle

Update:
So I realized the dtc cmd was actually outputting the dts file, so went ahead and just ignored the warning msgs and did rest of the steps. Unfortunately when I tried to use my new(edited) overlay file nothing happened and still stuck with a non-working display. Not all that Linux savvy myself, so prob missing something simple and hoping someone else can suggest way forward.

Note: I actually don't want to fix the " tft35a-overlay.dtb " file, as my screen uses this one and which is what would like help with: https://github.com/Elecrow-RD/Elecrow-LCD35/blob/master/elecrow35a-overlay.dtb