USB Type-C DisplayPort Alternate Mode Driver Coming To Linux 4.19

[Enverex]

Does anyone know if this was actually merged or not? I'm running 4.20.0-rc3 right now and having no luck with a monitor which supports Alternate Mode via USB-C, via the USB-C Thunderbolt 3 port on an Intel NUC.

[Venemo]

Interesting, is that USB-C device visible on lsusb as a video device of some sort? How about lspci or dmesg output when you connect it, if it's not too much trouble

It does not show up on lsusb, no.
lspci just shows the Intel GPU, but nothing fancy.

However I have the following ports in /sys/class/drm: card0-DP-1 card0-DP-2 card0-eDP-1
Where card0-eDP-1 is connected to the internal display and card0-DP-1 and card0-DP-2 are available for external displays (on whichever Type-C port that you prefer).

[starshipeleven]

Type-C to DisplayPort already works on my Dell XPS 9370. What exacty does this new driver do?

It deals with devices where it's not handled in firmware like in your case.

I don't understand why Intel in their infinite wisdom decided to even allow the choice of not using a firmware to deal with these things.

[numacross]

It also works on the non-Thunderbolt USB Type-C port so... not sure what it is. Most likely the firmware does its magic.

Interesting, is that USB-C device visible on lsusb as a video device of some sort? How about lspci or dmesg output when you connect it, if it's not too much trouble

[edwaleni]

This is great progress on the USB-C front in Linux. USB-C is still a misused connector standard by the hardware vendors and has caused a great deal of user confusion. Even on the Windows side, I can't tell you how many people get these USB-C dongles with a HDMI port on it that doesn't work. Device Managers will show a "USB_Billboard" issue because the OS can't locate an alt-mode. They are beginning to fill the return bins at BestBuy.

I am prepping a USB 3.1 Gen 2 test for my own consumption just to get a feel of where Linux is overall. Beware of cheap cables!

[Venemo]

That is most likely not using USB-C DisplayPort alternate mode, but Thunderbolt 3 DisplayPort mode instead, which is supported natively for quite some time.

USB-C has 4 alternate modes for video

It also works on the non-Thunderbolt USB Type-C port so... not sure what it is. Most likely the firmware does its magic.

[numacross]

Type-C to DisplayPort already works on my Dell XPS 9370. What exacty does this new driver do?

That is most likely not using USB-C DisplayPort alternate mode, but Thunderbolt 3 DisplayPort mode instead, which is supported natively for quite some time.

USB-C has 4 alternate modes for video

[boxie]

The 9370 does not have any NVidia hardware. I would never buy NVidia hardware. It just has an integrated Intel GPU.

So your dell has some firmware that is presenting the DRM interface then

[Venemo]

is it currently being done by an nvidia binary driver or the aforementioned firmware blobs that auto initialised?

The 9370 does not have any NVidia hardware. I would never buy NVidia hardware. It just has an integrated Intel GPU.

[boxie]

Type-C to DisplayPort already works on my Dell XPS 9370. What exacty does this new driver do?

is it currently being done by an nvidia binary driver or the aforementioned firmware blobs that auto initialised?