I7-8700 onboard HDMI port does not support 4K resolution

Submitted by jian-hong@endlessm.com

Assigned to Intel GFX Bugs mailing list

Link to original bug (#112018)

Description

Created attachment 145751
xrandr shows available resolustions

We have a desktop equipped with i7-8700. Its onboard HDMI port cannot support up to resolution 38402160 on Linux (mainline kernel 5.4-rc3+). But Windows supports (must do Windows update to latest which includes the graphic driver).

The graphic information

00:02.0 VGA compatible controller [0300]: Intel Corporation UHD Graphics 630 (Desktop) [8086:3e92] (prog-if 00 [VGA controller])
Subsystem: Acer Incorporated [ALI] UHD Graphics 630 (Desktop) [1025:124e]
Flags: bus master, fast devsel, latency 0, IRQ 138
Memory at a1000000 (64-bit, non-prefetchable) [size=16M]
Memory at 90000000 (64-bit, prefetchable) [size=256M]
I/O ports at 5000 [size=64]
[virtual] Expansion ROM at 000c0000 [disabled] [size=128K]
Capabilities: [40] Vendor Specific Information: Len=0c <?>
Capabilities: [70] Express Root Complex Integrated Endpoint, MSI 00
Capabilities: [ac] MSI: Enable+ Count=1/1 Maskable- 64bit-
Capabilities: [d0] Power Management version 2
Capabilities: [100] Process Address Space ID (PASID)
Capabilities: [200] Address Translation Service (ATS)
Capabilities: [300] Page Request Interface (PRI)
Kernel driver in use: i915
Kernel modules: i915

We also check the onboard display port. Display port can support up to resolution 38402160 on Linux.

Attachment 145751, "xrandr shows available resolustions":
xrandr.txt