I patched kernel 7.3-rc1 with the passive-VRR patches, but VRR is not
engaging while on the desktop, only in game.
On 01/09/2026 20:15, Zuo, Jerry wrote:
AMD General
-----Original Message-----
From: Adolfo <[email protected]>
Sent: Monday, August 31, 2026 14:49
To: Zuo, Jerry <[email protected]>; [email protected]
Cc: [email protected]; Wentland, Harry
<[email protected]>; Tomasz Pakuła
<[email protected]>; [email protected]
Subject: Re: [PATCH v4 0/4] HDMI 2.1 VRR and ALLM support
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I patched kernel 7.3-rc1, and I have KDE's Adaptive Sync property set to
Automatic (Always makes the display gamma flicker). VRR itself is only
engaged when entering a game.
My display (an LG C1 connected through an Onkyo RZ70 AVR) shows "fixed"
when VRR is not active. While this seems logical, it causes the display to go
blank every time I enter or exit a game, or, even worse, when I alt-tab while in
a game.
In my case, I can have periods of up to 10 seconds with no image while the
devices in the HDMI chain disagree with each other, and sometimes I lose the
image completely.
A kernel parameter to force VRR to always be enabled should be available.
This would prevent these signal-switching problems, and it is how "FreeSync"
actually works and also with the unofficial kernel patches for AMD HDMI 2.1
+ VRR on kernel 7.2.
There is also some evidence that keeping VRR active can avoid the mode-
switch behavior seen on some TVs when VRR is enabled or disabled.
Thanks for your feedback. Regarding to your concern, I've uploaded another
series of patches for "passive VRR". Please check and see if that works for you.
Regards,
Jerry
On 14/08/2026 17:43, Fangzhi Zuo wrote:
This series adds HDMI 2.1 gaming support to amdgpu: Variable Refresh
Rate
(VRR) derived from the HDMI Forum VSDB (HF-VSDB), and Auto Low-
Latency
Mode (ALLM). It builds on a drm/edid patch that parses the HF-VSDB
gaming capabilities into struct drm_hdmi_info.
- Patch 1 reports FreeSync from the AMD VSDB (existing mechanism).
- Patch 2 (drm/edid) parses the HF-VSDB VRR range and ALLM bit.
- Patch 3 enables VRR from the HF-VSDB when the AMD VSDB has no
range.
- Patch 4 signals ALLM_Mode in the HF-VSIF when Gaming-VRR is active.
v1:
https://lore.kernel.org/amd-gfx/20260730171754.704049-1-jerry.zuo@amd.
com/
v2:
https://lore.kernel.org/amd-gfx/[email protected]
om/
v3:
https://lore.kernel.org/amd-gfx/20260811003921.1398292-1-
jerry.zuo@amd
.com/
Changes since v3:
- Drop the content-type based ALLM heuristic. ALLM_Mode is now set
only
for the mandatory Gaming-VRR case (VRR_EN=1 with a sink that
advertises
ALLM), per HDMI 2.1 Section 7.6.6; it is no longer derived from the
content type.
Changes since v2:
- Fix coding-style issues in the VTEM info-packet code.
Fangzhi Zuo (3):
drm/amd/display: Add 2.1 FreeSync support for AMD VSDB EDID Block
drm/amd/display: Add HDMI 2.1 VRR support from HF-VSDB
drm/amd/display: Enable HDMI ALLM for Gaming-VRR
Tomasz Pakuła (1):
drm/edid: parse HDMI 2.1 gaming (ALLM/VRR) capabilities from
HF-VSDB
.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 5 +-
.../display/amdgpu_dm/amdgpu_dm_connector.c | 71 +++++++++++-
.../display/amdgpu_dm/amdgpu_dm_freesync.c | 41 +++++++
.../amd/display/modules/inc/mod_info_packet.h | 4 +
.../display/modules/info_packet/info_packet.c | 109 ++++++++++++++++++
drivers/gpu/drm/drm_edid.c | 42 +++++++
include/drm/drm_connector.h | 47 ++++++++
7 files changed, 317 insertions(+), 2 deletions(-)
base-commit: de2622bbc20276eaaaafa8fdbd374ace1ced28dc
