[PATCH] drm/amd/display: handle range offsets in VRR ranges

[Alex Deucher]

Need to check the offset bits for values greater than 255.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3203
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---

Can we just drop this code (at least for DP)?  drm_edid.c already handles
this properly in get_monitor_range().

 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 32efce81a5a74..c4fc65ba6b29b 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -11300,6 +11300,13 @@ void amdgpu_dm_update_freesync_caps(struct drm_connector *connector,
 				connector->display_info.monitor_range.min_vfreq = range->min_vfreq;
 				connector->display_info.monitor_range.max_vfreq = range->max_vfreq;
 
+				if (edid->revision >= 4) {
+					if (data->pad2 & DRM_EDID_RANGE_OFFSET_MIN_VFREQ)
+						connector->display_info.monitor_range.min_vfreq += 255;
+					if (data->pad2 & DRM_EDID_RANGE_OFFSET_MAX_VFREQ)
+						connector->display_info.monitor_range.max_vfreq += 255;
+				}
+
 				break;
 			}
 
-- 
2.44.0