[PATCH v2 3/4] drm/amd/display: Clean up FreeSync capability detection
From: Alex Huang
Date: Fri Jul 24 2026 - 12:30:50 EST
Many duplicate codes can be extracted to common code, fill
amdgpu_dm_connector fields outside of the DP/eDP, HDMI branches,
pull the VSDB data once using get_amd_vsdb() and then derive the refresh
rate ranges.
When a monitor advertises support for FreeSync, the refresh rate from
the AMD VSDB is used, otherwise, falls back on the monitor_range, either
EDID refresh rate range field or DisplayID VRR data.
Signed-off-by: Alex Huang <Alex.Huang2@xxxxxxx>
---
.../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 82 +++++++++----------
1 file changed, 38 insertions(+), 44 deletions(-)
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 fd9bb205c8f0..06ab1c2ef951 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -13707,7 +13707,7 @@ static int get_amd_vsdb(struct amdgpu_dm_connector *aconnector,
void amdgpu_dm_update_freesync_caps(struct drm_connector *connector,
const struct drm_edid *drm_edid, bool do_mccs)
{
- int i = 0;
+ bool has_vsdb = 0;
struct amdgpu_dm_connector *amdgpu_dm_connector =
to_amdgpu_dm_connector(connector);
struct dm_connector_state *dm_con_state = NULL;
@@ -13751,63 +13751,57 @@ void amdgpu_dm_update_freesync_caps(struct drm_connector *connector,
connector->display_info.monitor_range.max_vfreq == 0))
parse_edid_displayid_vrr(connector, edid);
- if (edid && (sink->sink_signal == SIGNAL_TYPE_DISPLAY_PORT ||
- sink->sink_signal == SIGNAL_TYPE_EDP)) {
- if (amdgpu_dm_connector->dc_link &&
- amdgpu_dm_connector->dc_link->dpcd_caps.allow_invalid_MSA_timing_param) {
- amdgpu_dm_connector->min_vfreq = connector->display_info.monitor_range.min_vfreq;
- amdgpu_dm_connector->max_vfreq = connector->display_info.monitor_range.max_vfreq;
- if (amdgpu_dm_connector->max_vfreq - amdgpu_dm_connector->min_vfreq > 10)
- freesync_capable = true;
+ has_vsdb = get_amd_vsdb(amdgpu_dm_connector, &vsdb_info) != 0;
+
+ if (has_vsdb) {
+ amdgpu_dm_connector->vsdb_info = vsdb_info;
+
+ /* copy refresh rate info as long as VSDB advertises FreeSync */
+ if (vsdb_info.freesync_supported) {
+ amdgpu_dm_connector->min_vfreq = vsdb_info.min_refresh_rate_hz;
+ amdgpu_dm_connector->max_vfreq = vsdb_info.max_refresh_rate_hz;
+
+ connector->display_info.monitor_range.min_vfreq =
+ vsdb_info.min_refresh_rate_hz;
+ connector->display_info.monitor_range.max_vfreq =
+ vsdb_info.max_refresh_rate_hz;
}
+ } else {
+ /* fall back to the base EDID range when there is no VSDB */
+ amdgpu_dm_connector->min_vfreq = connector->display_info.monitor_range.min_vfreq;
+ amdgpu_dm_connector->max_vfreq = connector->display_info.monitor_range.max_vfreq;
+ }
- get_amd_vsdb(amdgpu_dm_connector, &vsdb_info);
+ if (sink->sink_signal == SIGNAL_TYPE_DISPLAY_PORT ||
+ sink->sink_signal == SIGNAL_TYPE_EDP) {
+ if (amdgpu_dm_connector->dc_link &&
+ amdgpu_dm_connector->dc_link->dpcd_caps.allow_invalid_MSA_timing_param &&
+ amdgpu_dm_connector->max_vfreq - amdgpu_dm_connector->min_vfreq > 10)
+ freesync_capable = true;
if (vsdb_info.replay_mode) {
- amdgpu_dm_connector->vsdb_info.replay_mode = vsdb_info.replay_mode;
- amdgpu_dm_connector->vsdb_info.amd_vsdb_version = vsdb_info.amd_vsdb_version;
amdgpu_dm_connector->as_type = ADAPTIVE_SYNC_TYPE_EDP;
}
+ } else if (has_vsdb && sink->sink_signal == SIGNAL_TYPE_HDMI_TYPE_A) {
+ sink->edid_caps.freesync_vcp_code = vsdb_info.freesync_mccs_vcp_code;
- } else if (drm_edid && sink->sink_signal == SIGNAL_TYPE_HDMI_TYPE_A) {
- i = get_amd_vsdb(amdgpu_dm_connector, &vsdb_info);
- if (i) {
- amdgpu_dm_connector->vsdb_info = vsdb_info;
- sink->edid_caps.freesync_vcp_code = vsdb_info.freesync_mccs_vcp_code;
-
- if (vsdb_info.freesync_supported) {
- amdgpu_dm_connector->min_vfreq = vsdb_info.min_refresh_rate_hz;
- amdgpu_dm_connector->max_vfreq = vsdb_info.max_refresh_rate_hz;
- if (amdgpu_dm_connector->max_vfreq - amdgpu_dm_connector->min_vfreq > 10)
- freesync_capable = true;
-
- connector->display_info.monitor_range.min_vfreq = vsdb_info.min_refresh_rate_hz;
- connector->display_info.monitor_range.max_vfreq = vsdb_info.max_refresh_rate_hz;
- }
- }
+ if (vsdb_info.freesync_supported &&
+ amdgpu_dm_connector->max_vfreq - amdgpu_dm_connector->min_vfreq > 10)
+ freesync_capable = true;
}
if (amdgpu_dm_connector->dc_link)
as_type = dm_get_adaptive_sync_support_type(amdgpu_dm_connector->dc_link);
- if (as_type == FREESYNC_TYPE_PCON_IN_WHITELIST) {
- i = get_amd_vsdb(amdgpu_dm_connector, &vsdb_info);
- if (i) {
- amdgpu_dm_connector->vsdb_info = vsdb_info;
- sink->edid_caps.freesync_vcp_code = vsdb_info.freesync_mccs_vcp_code;
+ if (has_vsdb && as_type == FREESYNC_TYPE_PCON_IN_WHITELIST) {
+ sink->edid_caps.freesync_vcp_code = vsdb_info.freesync_mccs_vcp_code;
- if (vsdb_info.freesync_supported && vsdb_info.amd_vsdb_version > 0) {
- amdgpu_dm_connector->pack_sdp_v1_3 = true;
- amdgpu_dm_connector->as_type = as_type;
+ if (vsdb_info.freesync_supported && vsdb_info.amd_vsdb_version > 0) {
+ amdgpu_dm_connector->pack_sdp_v1_3 = true;
+ amdgpu_dm_connector->as_type = as_type;
- amdgpu_dm_connector->min_vfreq = vsdb_info.min_refresh_rate_hz;
- amdgpu_dm_connector->max_vfreq = vsdb_info.max_refresh_rate_hz;
- if (amdgpu_dm_connector->max_vfreq - amdgpu_dm_connector->min_vfreq > 10)
- freesync_capable = true;
-
- connector->display_info.monitor_range.min_vfreq = vsdb_info.min_refresh_rate_hz;
- connector->display_info.monitor_range.max_vfreq = vsdb_info.max_refresh_rate_hz;
- }
+ if (amdgpu_dm_connector->max_vfreq - amdgpu_dm_connector->min_vfreq > 10)
+ freesync_capable = true;
}
}
--
2.34.1