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 > > [You don't often get email from [email protected]. Learn why this is > important at https://aka.ms/LearnAboutSenderIdentification ] > > 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
