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[GUIDE] General Framebuffer Patching Guide (HDMI Black Screen Problem)

I have not experimented with HDMI->DP adapters. If you look at my HP EliteDesk 800 G4 Mini thread, you will notice that I needed to add device property "No-hda-gfx"...

Intel 630 and monitor connect via HDMI> DP direct cable because monitor only has DP port. Testing the HDMI-only TV is when I discovered the missing bug. Then I have tried a monitor with HDMI and the sleep works fine, as with the TV.
I have read your article before but I haven’t try No-hda-gfx. I'm going to test with that parameter and HDMI> DP cable. I will comment if that way the bug is also corrected. The loss of audio over HDMI is not important because my monitor has no audio.
 
I have not experimented with HDMI->DP adapters. If you look at my HP EliteDesk 800 G4 Mini thread, you will notice that I needed to add device property "No-hda-gfx"...

Yo say in your thread: "The config.plist included in the EliteDesk.zip archive attached to Post #1 adds device property "no-hda-gfx" to HDEF ( PciRoot(0x0)/Pci(0x1F,0x3) ). I needed to add this to prevent an AppleALC kernel panic when waking from sleep, because I am using DP->DVI adapters. While this prevents the kernel panic, it also disables sound over DP. If you are using DP / HDMI connectors without adapters, you should remove the "no-hda-gfx" property so that sound works over DP / HDMI."

I have added "no-hda-gfx" and the kernel panic returning from sleep effectively disappears but the sound is lost through HDMI. Now everything seems to make sense according to the text of your message:
- Intel HDMI to DisplayPort monitor> has HDMI audio output but has kernel panic when coming from sleep
- Intel HDMI to HDMI TV> has HDMI audio output and sleep works fine
- Intel HDMI to DisplayPort monitor with "no-hda-gfx"> sleep works fine but HDMI audio output is lost.
 
Hi, I´m running Catalina 10.15.6 on a Gigabyte H470M DS3H, it works pretty fine, but I can´t get accelerated graphics to work. Anyone can help, please?
 
@miliuco - I'm glad my suggestion worked! @CaseySJ - if adding device property "no-hda-gfx" is all that's needed to permit the use of a HDMI->DP adapter, maybe this should be noted in Post #1? I have added a note about this here.

@miliuco - You have quoted me correctly - that is what I said in my HP EliteDesk 800 G4 Mini Known Issues. That issue is specifically addressed to anyone who copies my config.plist, but is not using a video adapter with their connector. That known issue does not apply to you, since you are using an adapter (HDMI->DP). You need to add the "no-hda-gfx" property because you are using a HDMI->DP adapter.
 
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@miliuco - I'm glad my suggestion worked! @CaseySJ - if adding device property "no-hda-gfx" is all that's needed to permit the use of a HDMI->DP adapter, maybe this should be noted in Post #1? I have added a note about this here.

You have quoted me correctly - that is what I said in my HP EliteDesk 800 G4 Mini Known Issues. That issue is specifically addressed to anyone who copies my config.plist, but is not using a video adapter with their connector. That known issue does not apply to you, since you are using an adapter (HDMI->DP). You need to add the "no-hda-gfx" property because you are using a HDMI->DP adapter.
Thanks! A link to the post regarding no-hda-gfx has been added to the top of Preflight Checklist in Post #1.
 
@deeveedee and @CaseySJ Thank you so much for your help! In a few days I have learned a lot of things that I did not know. This is nice. Congratulations to both of you for your work.

Added info in the Post #1 of my thread about Z390 Aorus Elite.
 
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Hi, I´m running Catalina 10.15.6 on a Gigabyte H470M DS3H, it works pretty fine, but I can´t get accelerated graphics to work. Anyone can help, please?

Your card is also Intel UHD 630 as it says in your signature? You don't comment about the settings you are using to make the card work. You have a fairly new motherboard with a 470 chipset that is less tested on macOS than the 390 and earlier. I recommend you to open a new thread explaining how you have your configuration in regards to the card and what works well and what does not work.
 
Hey checotrevi

I have the same exact hardware for the current rig. I did use the defaults from below and all three ports seem to be somewhat working. They're finicky when I used HDMI->DVI, DP->HDMI or DP->DVI cable

I se you have different bus id for DP and different flags. I'm curious what kind of issues were you facing. Also is possible for you to share the generated XML patch?

Nice Thread... i was trying to fix my HDMI (2) and DP ports on my ASRock z390m-itx/ac following the recommendations in here just to find out that the spoiler for this board is wrong. At least those are not the right values for Display Port. After several tries and doing manual changes on clover i got the 3 ports to work. My final configuration is as follows in case someone is looking for this information.
 
Hi, I´m running Catalina 10.15.6 on a Gigabyte H470M DS3H, it works pretty fine, but I can´t get accelerated graphics to work. Anyone can help, please?

Hi could you please give me your efi folder
 
Hey checotrevi

I have the same exact hardware for the current rig. I did use the defaults from below and all three ports seem to be somewhat working. They're finicky when I used HDMI->DVI, DP->HDMI or DP->DVI cable

I se you have different bus id for DP and different flags. I'm curious what kind of issues were you facing. Also is possible for you to share the generated XML patch?

Hi Safehans...

This is very interesting... I started with the defaults and I was not able to make DP work under BUS ID 0x05. So I started to play with other values and 0x01 was the Bus Id that worked. Since then, I haven't found any issue and I am able to have up to 3 displays working simultaneously. Interesting that you have different values on same card... but if this works for you, leave it as it is.

In regards to the flags, I can't remember where I saw those values but they seem to work pretty good. Same thing with the pipe.

My first build was done using Clover, but I was having a lot of kernel panics on my boot and never felt confortable with this bootloader besides that NVRAM was not working at all. So I decided to move to OpenCore 0.6.0 and after cleaning it up, i am very very happy with the result. OpenCore seems to be a more clean and straight forward solution. No panics, no errors, EVERYTHING works as it should. All USB ports, Ethernets, Audio, Bluetooth, WiFi, video, sleep/wake, NVRAM, etc., etc.

I can tell you, it boots pretty much like a Mac, i was able to hide the bootloader menu and when you turn it on, it goes straight to the apple logo.

Yesterday i was able to install Catalina update without any issue. It took longer than the typical update though (i thing this one was a big one).

Screen Shot 2020-09-03 at 10.40.10 PM.png
 
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