#336 PTH-660 input lag over teradici extender
Hi
I have been having an issue with the PTH-660 under linux.
The device is connected via a teradici tera2 extender (zero client and hostcard) in USB pass through mode.
Network latency is < 1ms
The pointer will lag behind the sylus position by a noticable amount.
When directly connected to the linux host the driver works as expected
A Windows installation also connected to the tablet via a teradici extender does not have the issue.
Older tablets work as expected on Linux and Windows.
As the issue is only present with the linux installation I suspect that this issue may be with input-wacom.
Teradici have also been made aware of the issue.
Our installation is:
Scientific Linux release 6.7 (Carbon)
Kernel 3.2.6.32-573.18.1
wacom software versions (linux):
wacomexpresskeys-0.4.2-3.el6.x86_64
libwacom-0.24-2.el6.x86_64
libwacom-data-0.24-2.el6.noarch
kmod-wacom-0.35.1-xxxx1.el6.x86_64
xorg-x11-drv-wacom-0.34.0-1.el6.x86_64
Windows driver version 6.3.20-7
Please let me know if there is any diagnostics data that can be captured that may help.
Thanks
James.
Discussion
Hi James,
We are aware of the issue too. You'll need to get an update from Teradici to make your new device work properly. The new series of Intuos Pro has not been added to their client for Linux.
Oh thanks, this is good to hear. We've hit this as well with the 16" tablet.
Hi Ping,
My reply to your comment 28/04/17 didn't post here.
Hi Ping,
I have been pushing Teradici to support the new devices. This will (eventually) enable the use of their local wacom driver on the extender. This could take a while.
The more common mode (for me) to run the extender in is pass through mode which does not rely on any driver support within the teradici extender or teradici software on the host. This is where I am seeing a difference in behavior between the linux and windows driver.
The Windows driver functions correctly and there is no input lag.
The Linux driver functions but with significant delay.
Which part of the driver would be most significantly affected by the increased delay introduced by the network based extender? I wonder if it would be possible to reduce the effect that network delay has on the driver?
We have been able to use older tablets in pass through mode with a network delay of approx 6ms and no noticeable delay. Would you be able to help me understand what has changed with the new tablet that would make it so much more affected by network delay?
The windows driver does not seem to be adversely affected by the increased delay between the tablet and the hosts. Is there a difference in the way the tablet is accessed by the windows driver?
I do appreciate that this is a problem introduced by inserting equipment between the tablet and the host. If the results were consistent between operating systems the issue would be firmly with teradici. Since one OS (Windows) functions correctly I am exploring the possibility of gaining sufficient improvement with a modification to the driver.
Thank you for your help
James.
Hi James,
I understand what you were talking about. I worked with Teradici developers to resolve the issue on Linux for the Wacom devices that you don't see the issue. But, as I mentioned before, the solution is not in the client for the new devices you are using. And, the solution/workaround is Linux specific.
I've forwarded your message to Teradici to see if they have other suggestions for us.