Fedora 35 super laggy with spam on dmesg only somehow working on Wayland

[kamdeb6x3]

Fedora 35 on 5.15.5-200.fc35.x86_64 kernel DisplayLink → fedora-34-displaylink-1.9.1-1.x86_64.rpm EVDI → https://github.com/nilathedragon/evdi (Only this EVDI version I can compile on this version of kernel.) Host → Nitro AN515-42 V1.18 DE → Plasma 5.23.3 WM → KWin CPU → AMD Ryzen 5 2500U with Radeon Vega Mobile Gfx (8) @ 2.000GHz

As I'm trying to connect Toshiba Dynadock PA3927E-1PRP USB3 via HDMI to my second monitor it works super laggy on Wayland.

It runs even worse on X11.

I cannot compile EVDI → https://github.com/DisplayLink/evdi because it gives me an error: drm/drm.h: No such file or directory

When dock station is connected an second monitor is active it spams my dmesg with:

[  499.354954] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  499.444852] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  499.541495] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  499.638264] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  499.734476] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  499.826877] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  499.919832] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  500.010354] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  500.102204] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  500.191099] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  500.278920] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  500.368719] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  500.460263] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  500.547712] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device

And it goes on and on...

[tberta]

Have you tried the following options:

// Modify /etc/modprobe.d/evdi.conf file to have the following content:
options evdi initial_loglevel=0 initial_device_count=4 disable_texture_import=1

And restart. On my system, the kernel messages “cannot be used for peer-to-peer DMA…” disappeared after adding the following option: disable_texture_import=1

[displaylink-emajewsk]

Hi. Instead of doing disable_texture_import=1. Could you please try the current devel and report the results?

[kamdeb6x3]

Okay there is much improvement, I can compile devel branch and I works better on Wayland but still super laggy on X11. I see no spam on dmesg also so that's nice. Thank you very much!

[kamdeb6x3]

But there showed up another spam on dmesg...

[  497.925888] evdi: [W] evdi_framebuffer_sanitize_rect:76 Wrong clip rect: x2 > fb.width
[  497.929758] evdi: [W] evdi_framebuffer_sanitize_rect:66 Wrong clip rect: x1 > fb.width
[  497.929764] evdi: [W] evdi_framebuffer_sanitize_rect:76 Wrong clip rect: x2 > fb.width
[  497.929765] evdi: [W] evdi_framebuffer_sanitize_rect:66 Wrong clip rect: x1 > fb.width
[  497.929766] evdi: [W] evdi_framebuffer_sanitize_rect:76 Wrong clip rect: x2 > fb.width
[  497.933788] evdi: [W] evdi_framebuffer_sanitize_rect:66 Wrong clip rect: x1 > fb.width
[  497.933793] evdi: [W] evdi_framebuffer_sanitize_rect:76 Wrong clip rect: x2 > fb.width
[  497.933795] evdi: [W] evdi_framebuffer_sanitize_rect:66 Wrong clip rect: x1 > fb.width

[displaylink-emajewsk]

Is this on X11 or Wayland?

[kamdeb6x3]

On wayland because as I wrote on X11 it's unusable

[displaylink-emajewsk]

Sure. I don't think we can do much about X11 on amdgpu in the near future, unfortunately.

Do you experience any visual glitches? It's just a warning this time, if you wish, those can be turned off with sudo sh "echo 2 > /sys/devices/evdi/loglevel"

[kamdeb6x3]

Okay it's so close to working but now there is again this dmesg spam:

[  420.081910] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  420.166172] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  421.713808] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  421.806414] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  421.891575] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  421.971001] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  422.052956] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  423.087108] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  423.207249] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  423.298123] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  425.230711] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device

Is it possible that log spam is related to lag??

[groovyman]

Salut,

this turns out to be a real dejavue. You (@kamdeb6x3) may take a deeper look at your notebook, iff it does support for UCB-C DP (1.2) check out the technical doumentation. If yes, you may rely on the wrong technology, try to get a MST hub/docking station or get a USB-C DP to DP Cable and forget DisplayLink.

It is nice to see that the DisplayLink staff is tryning hard to get the driver working, Thank you all, really!! Your work is still desired, so do not get me wrong.

Owner of newer notebooks (with UCB-C (Alt) DP) should better rely on MST (especially also for Windows User), because it simply use DP functionality and does not need any driver and requires no additonal CPU hog to copy data through a USB cable.

So Kamil , if your Notebook supports for DP1.2 over USB-C, the it is worth to try this, i can not guarantee, that it is working out of the box (mine Thinkbook 16p still has lot of issues with its DP 1.4, but i am working on it). Anyway there are some users of notebooks, that are equipeedwith a USB-C DP1.2 connectors, that told me, that they are using MST. The DP (Alt)/MST solution is less expensive than DisplayLink docking-station and iff they work, you won't go back (to DisplayLink) anymore.

[groovyman]

Okay it's so close to working but now there is again this dmesg spam:

[  420.081910] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  420.166172] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  421.713808] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  421.806414] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  421.891575] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  421.971001] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  422.052956] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  423.087108] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  423.207249] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  423.298123] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device
[  425.230711] evdi evdi.0: cannot be used for peer-to-peer DMA as it is not a PCI device

Is it possible that log spam is related to lag??

no, it seems to be a bug to me!

[kamdeb6x3]

Unfortunately my laptop only has one USB3 port other two are USB2 and it has USB-C but without Thunderbolt support. Correct me if I'm wrong and your talking about other technology that I should take a look at in notebook documentation.

[groovyman]

Unfortunately my laptop only has one USB3 port other two are USB2 and it has USB-C but without Thunderbolt support. Correct me if I'm wrong and your talking about other technology that I should take a look at in notebook documentation.

Salut, umpf .. ok, what model is your notebook?

As far as i know is: Thunderbold3 is not USB-C DP. Thunderbold 3 maps the PCIe3 Standard intro a cable, that looks like a USB-C. USB-C (Alt) DP maps the DisplayPort signal parallel to the USB3 signals on different line. So we might have:

• USB3 with USB3 Gen2 with 10Mbit and USB3 Gen2x2 that comes with the double throughput.
• USB3 (Alt) DP that uses 4 lines (am i right ??), that transports the DisplayPort protocols
• Thunderbold 3/4 that is completly different and only available for Apple and some mondern Intel-Notebooks.

See [the conference in 2015]{https://youtu.be/6301tGNs9Dc} Yep MST is great and seems to be a bit underquoted.

[kamdeb6x3]

Okaaaay you made me intrested! I found on official Acer website this information: USB Type-C port supporting: USB 3.1 Gen 1 (up to 5 Gbps) source: https://www.acer.com/datasheets/2018/4876/AN515-42/NH.Q3RAA.002.html

Notebook model: Acer Nitro 5 AN515-42

[groovyman]

That may be not enough, you need DP Alt Mode ! https://www.benq.com/en-us/knowledge-center/knowledge/usb-c-introduction-what-is-dp-alt-mode.html#S3

Anyway i german user reported, that ACER does not know, what hardware they ship to the customer. The internal spec said no DP but the customer found out, that this was wrong. https://community.acer.com/de/discussion/comment/699667#Comment_699667

But maybe the user had overseen, that he was using a Displaylink device.

[kamdeb6x3]

Yeeeah Acer <3 Anyway so I have no other options left besides DisplayLink dock?

[jakub-prussak-synaptics]

I will close the issue for the time being, let us know if the problems are still appearing.