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authorHarold Sun <Harold.Sun@amd.com>2025-06-19 14:52:54 -0400
committerAlex Deucher <alexander.deucher@amd.com>2025-06-30 11:59:00 -0400
commitfe7645d22bc0f7c1558296538ec49987bf268ef6 (patch)
tree9889d25a623f5ea6008c710959acea95b210be62 /drivers/gpu/drm/amd/display/modules
parent660a467a5e7366cd6642de61f1aaeaf0d253ee68 (diff)
drm/amd/display: Added case for when RR equals panel's max RR using freesync
[WHY] Rounding error sometimes occurs when the refresh rate is equal to a panel's max refresh rate, causing HDMI compliance failures. [HOW] Added a case so that we round up to avoid v_total_min to be below a panel's minimum bound. Reviewed-by: Jun Lei <jun.lei@amd.com> Signed-off-by: Harold Sun <Harold.Sun@amd.com> Signed-off-by: Ray Wu <ray.wu@amd.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm/amd/display/modules')
-rw-r--r--drivers/gpu/drm/amd/display/modules/freesync/freesync.c8
1 files changed, 8 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 6a939f2f2fb9..71efd2770c99 100644
--- a/drivers/gpu/drm/amd/display/modules/freesync/freesync.c
+++ b/drivers/gpu/drm/amd/display/modules/freesync/freesync.c
@@ -155,6 +155,14 @@ unsigned int mod_freesync_calc_v_total_from_refresh(
v_total = div64_u64(div64_u64(((unsigned long long)(
frame_duration_in_ns) * (stream->timing.pix_clk_100hz / 10)),
stream->timing.h_total), 1000000);
+ } else if (refresh_in_uhz >= stream->timing.max_refresh_in_uhz) {
+ /* When the target refresh rate is the maximum panel refresh rate
+ * round up the vtotal value to prevent off-by-one error causing
+ * v_total_min to be below the panel's lower bound
+ */
+ v_total = div64_u64(div64_u64(((unsigned long long)(
+ frame_duration_in_ns) * (stream->timing.pix_clk_100hz / 10)),
+ stream->timing.h_total) + (1000000 - 1), 1000000);
} else {
v_total = div64_u64(div64_u64(((unsigned long long)(
frame_duration_in_ns) * (stream->timing.pix_clk_100hz / 10)),