Debian xfce scale display

#1

After making the spi display to work as framebuffer in Ubuntu server, i tried to install the same thing in Debian and got the os recognize the display. However, given that it sees my display as 320x240, is there a way to scale the display, like running 1280x720 in 320x240 mode.
I tried it with xrandr but it doesn’t work.

20221016_095416
20221016_095416.jpg2268×4032 1.66 MB

Working SPI Display
#2

What are the xrandr commands you tried that don’t work?

Did you want to scale the whole desktop to fit the screen, or did you want to still be able to easily read words? You can pan a 320x240 ‘viewport’ which follows the mouse around a 1280x720 desktop, which lets you see 1:1 pixels and everything remains readable (but you see less of it at any time). Or you can set the scale to map any resolution desktop onto any resolution display-- but in this case, at that scaling factor-- 3:1 vertical and 4:1 horizontal-- I think it won’t be very usable until you turn up the font sizes and/or DPI. And even that might still allow UI elements like scroll bars to be tiny and un-targetable unless you choose a HiDPI theme that deliberately makes them larger.

The first option is described here: https://sfxpt.wordpress.com/2011/02/02/panning-using-xrandr/

And the second, here: https://unix.stackexchange.com/questions/596887/how-to-scale-the-resolution-display-of-the-desktop-and-or-applications

I hadn’t ever tried that, but it works here. Of course the text gets tiny and gritty. xrandr --output DVI-D-0 --scale 2x2 changed my desktop area to a 3840x2160 virtual screen and stuffed it into a 1080p LCD.

If that’s what you’ve already tried, I apologize… then, maybe the xrandr extension isn’t working.

#3

Thanks for the reply. I would prefer the latter. And indeed i have tried xrandr --output default --scale 4x3 and just spits the error:

xrandr: Failed to get size of gamma for output default
xrandr: screen cannot be larger than 320x240 (desired size 1280x720)
#4

A web search for “xrandr: Failed to get size of gamma” turns up lots of problems where the minimum and maximum and current resolution are all the same numbers, much like what happens to you. I would try choosing the mode in xorg.conf so that it’s correct from the beginning, and xrandr would not be needed, but I don’t know how to define a scaled display. You might be able to set the initial mode to 1280x720 and set the scale afterward with xrandr to make it fit into the LCD.