Comment 0 for bug 2009767

Revision history for this message
Kai-Chuan Hsieh (kchsieh) wrote : external HDMI monitor is laggy on NV reverse PRIME system

When the graphic mode is on-demand mode and plug in the monitor to HDMI port, there are two issue occures:
1. External monitor's screen is very laggy in external monitor mode only.
2. External monitor's screen sometimes (~50%) will be blak in join display mode.

[Steps to reproduce]
1. Boot in OS
2. Plug in the external monitor in HDMI port
3. Find the cursor moving in external monitor is laggy

[Additional information]
Feedback from NV:

An NVIDIA driver built with the features needed to get rid of the laggy monitor problem causes Xorg to crash. There's a patch for Xorg to fix the crash ( and it was first included in the release.
Since the older X servers crash, NVIDIA deliberately does a version check in the driver and enables these features for Xorg servers that are known to work, i.e. or higher.

This unfortunately prevents backporting the fix to Engineering has chosen this approach since a crash is worse than the low FPS lag and the user might lose work merely by plugging/unplugging displays. If it was about a performance degradation, slight corruption, or something non-fatal, we wouldn't need to check Xorg version