From: Bayan Zabihiyan <bayan.zabihi...@amd.com>

[Why]
The math on deciding on how many
"frames to insert" sometimes sent us over the max refresh rate.
Also integer overflow can occur if we have high refresh rates.

[How]
Instead of clipping the  frame duration such that it doesn’t go below the min,
just remove a frame from the number of frames to insert. +
Use unsigned long long for intermediate calculations to prevent
integer overflow.

Signed-off-by: Bayan Zabihiyan <bayan.zabihi...@amd.com>
Reviewed-by: Aric Cyr <aric....@amd.com>
Acked-by: Leo Li <sunpeng...@amd.com>
---
 .../amd/display/modules/freesync/freesync.c   | 27 ++++++++++++-------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/modules/freesync/freesync.c 
b/drivers/gpu/drm/amd/display/modules/freesync/freesync.c
index 19b1eaebe484..000a9db9dad8 100644
--- a/drivers/gpu/drm/amd/display/modules/freesync/freesync.c
+++ b/drivers/gpu/drm/amd/display/modules/freesync/freesync.c
@@ -433,6 +433,12 @@ static void apply_below_the_range(struct core_freesync 
*core_freesync,
                /* Either we've calculated the number of frames to insert,
                 * or we need to insert min duration frames
                 */
+               if (last_render_time_in_us / frames_to_insert <
+                               in_out_vrr->min_duration_in_us){
+                       frames_to_insert -= (frames_to_insert > 1) ?
+                                       1 : 0;
+               }
+
                if (frames_to_insert > 0)
                        inserted_frame_duration_in_us = last_render_time_in_us /
                                                        frames_to_insert;
@@ -885,8 +891,8 @@ void mod_freesync_build_vrr_params(struct mod_freesync 
*mod_freesync,
        struct core_freesync *core_freesync = NULL;
        unsigned long long nominal_field_rate_in_uhz = 0;
        unsigned int refresh_range = 0;
-       unsigned int min_refresh_in_uhz = 0;
-       unsigned int max_refresh_in_uhz = 0;
+       unsigned long long min_refresh_in_uhz = 0;
+       unsigned long long max_refresh_in_uhz = 0;
 
        if (mod_freesync == NULL)
                return;
@@ -913,7 +919,7 @@ void mod_freesync_build_vrr_params(struct mod_freesync 
*mod_freesync,
                min_refresh_in_uhz = nominal_field_rate_in_uhz;
 
        if (!vrr_settings_require_update(core_freesync,
-                       in_config, min_refresh_in_uhz, max_refresh_in_uhz,
+                       in_config, (unsigned int)min_refresh_in_uhz, (unsigned 
int)max_refresh_in_uhz,
                        in_out_vrr))
                return;
 
@@ -929,15 +935,15 @@ void mod_freesync_build_vrr_params(struct mod_freesync 
*mod_freesync,
                return;
 
        } else {
-               in_out_vrr->min_refresh_in_uhz = min_refresh_in_uhz;
+               in_out_vrr->min_refresh_in_uhz = (unsigned 
int)min_refresh_in_uhz;
                in_out_vrr->max_duration_in_us =
                                calc_duration_in_us_from_refresh_in_uhz(
-                                               min_refresh_in_uhz);
+                                               (unsigned 
int)min_refresh_in_uhz);
 
-               in_out_vrr->max_refresh_in_uhz = max_refresh_in_uhz;
+               in_out_vrr->max_refresh_in_uhz = (unsigned 
int)max_refresh_in_uhz;
                in_out_vrr->min_duration_in_us =
                                calc_duration_in_us_from_refresh_in_uhz(
-                                               max_refresh_in_uhz);
+                                               (unsigned 
int)max_refresh_in_uhz);
 
                refresh_range = in_out_vrr->max_refresh_in_uhz -
                                in_out_vrr->min_refresh_in_uhz;
@@ -948,17 +954,18 @@ void mod_freesync_build_vrr_params(struct mod_freesync 
*mod_freesync,
        in_out_vrr->fixed.ramping_active = in_config->ramping;
 
        in_out_vrr->btr.btr_enabled = in_config->btr;
+
        if (in_out_vrr->max_refresh_in_uhz <
                        2 * in_out_vrr->min_refresh_in_uhz)
                in_out_vrr->btr.btr_enabled = false;
+
        in_out_vrr->btr.btr_active = false;
        in_out_vrr->btr.inserted_duration_in_us = 0;
        in_out_vrr->btr.frames_to_insert = 0;
        in_out_vrr->btr.frame_counter = 0;
        in_out_vrr->btr.mid_point_in_us =
-                       in_out_vrr->min_duration_in_us +
-                               (in_out_vrr->max_duration_in_us -
-                               in_out_vrr->min_duration_in_us) / 2;
+                               (in_out_vrr->min_duration_in_us +
+                                in_out_vrr->max_duration_in_us) / 2;
 
        if (in_out_vrr->state == VRR_STATE_UNSUPPORTED) {
                in_out_vrr->adjust.v_total_min = stream->timing.v_total;
-- 
2.22.0

_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx

Reply via email to