[Why]
Chrontel CH7218 found in Ugreen DP -> HDMI 2.1 adapter (model 85564)
works perfectly with VRR after testing. VRR and FreeSync compatibility
is explicitly advertised as a feature so it's addition is a formality.

Support FreeSync info packet passthrough and "generic" HDMI VRR.

[How]
Add CH7218's ID to dm_helpers_is_vrr_pcon_allowed()

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4773

Signed-off-by: Tomasz Pakuła <tomasz.pakula.oficjalny@gmail.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 1 +
 drivers/gpu/drm/amd/display/include/ddc_service_types.h   | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
index cb8a2855ac10..690558584a0f 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
@@ -1396,6 +1396,7 @@ bool dm_helpers_is_vrr_pcon_allowed(const struct dc_link *link, const struct drm
 	case DP_BRANCH_DEVICE_ID_0060AD:
 	case DP_BRANCH_DEVICE_ID_00E04C:
 	case DP_BRANCH_DEVICE_ID_90CC24:
+	case DP_BRANCH_DEVICE_ID_2B02F0:
 		return true;
 	}
 
diff --git a/drivers/gpu/drm/amd/display/include/ddc_service_types.h b/drivers/gpu/drm/amd/display/include/ddc_service_types.h
index 1c603b12957f..e838f7c1269c 100644
--- a/drivers/gpu/drm/amd/display/include/ddc_service_types.h
+++ b/drivers/gpu/drm/amd/display/include/ddc_service_types.h
@@ -36,6 +36,7 @@
 #define DP_BRANCH_DEVICE_ID_006037 0x006037
 #define DP_BRANCH_DEVICE_ID_001CF8 0x001CF8
 #define DP_BRANCH_DEVICE_ID_0060AD 0x0060AD
+#define DP_BRANCH_DEVICE_ID_2B02F0 0x2B02F0 /* Chrontel CH7218 */
 #define DP_BRANCH_HW_REV_10 0x10
 #define DP_BRANCH_HW_REV_20 0x20
 
-- 
2.52.0