Generic USB Display Driver "GUD" Slated For Linux 5.13

[phoronix]

Phoronix: Generic USB Display Driver "GUD" Slated For Linux 5.13

The Generic USB Display Driver "GUD" has just been sent in as part of the latest DRM-Misc-Next material to DRM-Next which in turn will land for Linux 5.13. The Generic USB Display Driver is nifty and allows for opening up possibilities like turning a Raspberry Pi Zero into a USB to HDMI display adapter among other fun use-cases...

https://www.phoronix.com/scan.php?pa...splay-GUD-5.13

[chuckula]

If you are new to using a USB display driver then I suggest that you git GUD N00b.

[skeevy420]

Dammit. I came here to make a git gud joke.

[Vistaus]

Dammit. I came here to make a git gud joke.

It better be a GUD one if you want to beat chuckula.

[nerdopolis]

Cool. You can probably achieve actual practical Wayland multiseat support with this. (Each seat needs a separate /dev/dri/cardX device. While you could use DisplayLink, only older v2 devices work natively, because v3 needs that half closed driver

[kpedersen]

Dammit. I came here to make a git gud joke.

Gud grief, these puns are terrible!

On a less serious note, I am really looking forward to having a play with this. I have far more Raspberry Pis than GPUs these days (I have no idea how I seem to inherit them somehow) and since most of my day to day usage is fairly boring in terms of graphics, this seems perfect.

Basically just a read-only install of Raspbian with this set up that I can just plug in and out will be great. I am also fairly certain the BSDs will get a driver semi soon because there is no real blobs or undocumented hardware involved.

[caligula]

Cool. You can probably achieve actual practical Wayland multiseat support with this. (Each seat needs a separate /dev/dri/cardX device. While you could use DisplayLink, only older v2 devices work natively, because v3 needs that half closed driver

What's wrong with VNC/RDP? Doesn't Wayland support background sessions?

[[email protected]]

What's wrong with VNC/RDP? Doesn't Wayland support background sessions?

Not sure how VNC/RDP would help with that? TBH, I am not sure what wayland changes in that equation.

You can have background sessions, but here the idea is to drive multiple {screen+mouse+keyboard+USB} combos, each logged into a separate user account, from a single computer. AKA multiseat.

Although loginctl allows assigning multiple outputs from the same graphics card to different seats, it never worked in my experience, and you have to use different cards. Here, this would be considered a different card.

The only thing I'm left wondering is if this couldn't go a few steps further, and expose the remote VA-API and hardware planes, all in the name of saving bandwidth (decode video on the pi, so send it compressed trough USB).

[caligula]

Not sure how VNC/RDP would help with that? TBH, I am not sure what wayland changes in that equation.

You can start a virtual X session and log in via VNC (Xvfb, x11vnc). For example start the X session on the larger PC, run the X apps on the PC, then use a RPi with VNC client as the human/compute interface.

[[email protected]]

You can start a virtual X session and log in via VNC (Xvfb, x11vnc). For example start the X session on the larger PC, run the X apps on the PC, then use a RPi with VNC client as the human/compute interface.

All right, but

• That's not exactly multiseat in my view
• You can very much do it with wayland. In sway for instance, all that's needed is adding a "headless" output to your config

You are right, one could use a RPi as a thin client. Thinking more about this, this would be more or less the same as this "GUD" driver, indeed. Latency and bandwidth would be severely constrained in both cases, so I guess this would be suitable for office work, but not shooter games.

However, configuring a VNC client and server sounds more complicated than configuring a USB gadget, that you can then bring to another place and have it work OOTB.