drm/amd/display: Make sure v_total_min and max not less than v_total.

Signed-off-by: Yongqiang Sun <yongqiang.sun@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/display/modules/freesync/freesync.c b/drivers/gpu/drm/amd/display/modules/freesync/freesync.c
index 94566c0a0e62..5c6de723da5d 100644
--- a/drivers/gpu/drm/amd/display/modules/freesync/freesync.c
+++ b/drivers/gpu/drm/amd/display/modules/freesync/freesync.c
@@ -347,6 +347,7 @@ static void calc_vmin_vmax(struct core_freesync *core_freesync,
 {
         unsigned int min_frame_duration_in_ns = 0, max_frame_duration_in_ns = 0;
         unsigned int index = map_index_from_stream(core_freesync, stream);
+        uint32_t vtotal = stream->timing.v_total;
 
         min_frame_duration_in_ns = ((unsigned int) (div64_u64(
                                         (1000000000ULL * 1000000),
@@ -362,6 +363,17 @@ static void calc_vmin_vmax(struct core_freesync *core_freesync,
         *vmin = div64_u64(div64_u64(((unsigned long long)(
                         min_frame_duration_in_ns) * stream->timing.pix_clk_khz),
                         stream->timing.h_total), 1000000);
+
+        /* In case of 4k free sync monitor, vmin or vmax cannot be less than vtotal */
+        if (*vmin < vtotal) {
+                ASSERT(false);
+                *vmin = vtotal;
+        }
+
+        if (*vmax < vtotal) {
+                ASSERT(false);
+                *vmax = vtotal;
+        }
 }
 
 static void calc_v_total_from_duration(const struct dc_stream *stream,