This is a good idea. It resets the DisplayPort path without affecting the PCIe tunneling. That means the USB stuff should continue to work if it was working?
Reseting the DisplayPorts is required for the Dell 5K in macOS. Unplugging the cables works but it's easier to turn off the display, wait a few seconds, then turn it on to get 5K. So a similar thing would work for the LG if the Nvidia thinks it's a Dell (assuming Nvidia doesn't do what's required for 5K displays that are not the Dell). The LG doesn't have a power button, so disconnecting the DisplayPort cables is the only thing you can do.
Yes, the audio and brightness adaptor take no effect, only the screen takes.
I almost understand the DELL's special codes, it is for hot-plug-interrupt. call stack
NVDA::doHotplugInterruptService(OSObject*, IOInterruptEventSource*, int)
IOInterruptEventSource::interruptEventSource(OSObject*, void (*)(OSObject*, IOInterruptEventSource*, int), IOService*, int)
NVDA::doDriverIO(unsigned int, void*, unsigned int, unsigned int)
codes base logic should be:
if( _NvRmControl( 0x730241) !=0 )
{
if(nv_spanmodepolicy==1 && isdellup2715k())
{
while(int i=0i < (_NvRmControl(0x730122,x,y,z)==0x66)
iosleep(x);
bool is_ok = check_if_has_two_display_with_dell_product_id();
if(is_ok)
{
get_info_from_nvVGPUTable();
get_info_from_kmodinfo();
merge_two_display_info_into_one();
while(int i=0i < (_NvRmControl(0x730122,x,y,z)==0x66)
iosleep(x);
}
}
}
I think patching this place should not take othe side-effect.
the only problem is the signal seems not unstable, it just last a few seconds, then it go black.
Still figuring why ..
