diff --git a/src/amd/common/nir/ac_nir.h b/src/amd/common/nir/ac_nir.h
index 1f53c0b7daa..46635909705 100644
--- a/src/amd/common/nir/ac_nir.h
+++ b/src/amd/common/nir/ac_nir.h
@@ -271,15 +271,13 @@ typedef struct {
     * generate AMD-specific intrinsics.
     */
    /* System values. */
-   bool force_persp_sample_interp;
-   bool force_linear_sample_interp;
    bool force_persp_center_interp;
    bool force_linear_center_interp;
    bool interpolate_at_sample_force_center;
    bool load_sample_positions_always_loads_current_ones;
    bool dynamic_rasterization_samples;
    int force_front_face; /* 0 -> keep, 1 -> set to true, -1 -> set to false */
-   unsigned ps_iter_samples;
+   unsigned ps_iter_samples; /* >= 2 forces sample interpolation, affects sample_mask_in lowering */
 
    /* fbfetch_output */
    bool fbfetch_is_1D;
diff --git a/src/amd/common/nir/ac_nir_lower_ps_early.c b/src/amd/common/nir/ac_nir_lower_ps_early.c
index ce61485b98a..320e406d9dc 100644
--- a/src/amd/common/nir/ac_nir_lower_ps_early.c
+++ b/src/amd/common/nir/ac_nir_lower_ps_early.c
@@ -48,19 +48,19 @@ get_baryc_var(nir_builder *b, nir_intrinsic_op baryc_op, enum glsl_interp_mode m
    switch (baryc_op) {
    case nir_intrinsic_load_barycentric_pixel:
       if (mode == INTERP_MODE_NOPERSPECTIVE) {
-         return get_baryc_var_common(b, s->options->force_linear_sample_interp, &s->linear_center,
+         return get_baryc_var_common(b, s->options->ps_iter_samples > 1, &s->linear_center,
                                      "linear_center");
       } else {
-         return get_baryc_var_common(b, s->options->force_persp_sample_interp, &s->persp_center,
+         return get_baryc_var_common(b, s->options->ps_iter_samples > 1, &s->persp_center,
                                      "persp_center");
       }
    case nir_intrinsic_load_barycentric_centroid:
       if (mode == INTERP_MODE_NOPERSPECTIVE) {
-         return get_baryc_var_common(b, s->options->force_linear_sample_interp ||
+         return get_baryc_var_common(b, s->options->ps_iter_samples > 1 ||
                                      s->options->force_linear_center_interp, &s->linear_centroid,
                                      "linear_centroid");
       } else {
-         return get_baryc_var_common(b, s->options->force_persp_sample_interp ||
+         return get_baryc_var_common(b, s->options->ps_iter_samples > 1 ||
                                      s->options->force_persp_center_interp, &s->persp_centroid,
                                      "persp_centroid");
       }
@@ -91,12 +91,9 @@ init_interp_param(nir_builder *b, lower_ps_early_state *s)
 {
    b->cursor = nir_before_cf_list(&b->impl->body);
 
-   if (s->options->force_persp_sample_interp) {
+   if (s->options->ps_iter_samples > 1) {
       set_interp_vars(b, nir_load_barycentric_sample(b, 32, .interp_mode = INTERP_MODE_SMOOTH),
                       s->persp_center, s->persp_centroid);
-   }
-
-   if (s->options->force_linear_sample_interp) {
       set_interp_vars(b, nir_load_barycentric_sample(b, 32, .interp_mode = INTERP_MODE_NOPERSPECTIVE),
                       s->linear_center, s->linear_centroid);
    }
diff --git a/src/gallium/drivers/radeonsi/si_shader.c b/src/gallium/drivers/radeonsi/si_shader.c
index 35cc931e513..968caf7f48e 100644
--- a/src/gallium/drivers/radeonsi/si_shader.c
+++ b/src/gallium/drivers/radeonsi/si_shader.c
@@ -2482,14 +2482,16 @@ static struct nir_shader *si_get_nir_shader(struct si_shader *shader, struct si_
       shader->info.ps_colors_read = info.colors_read;
 
       ac_nir_lower_ps_early_options early_options = {
-         .force_persp_sample_interp = key->ps.part.prolog.force_persp_sample_interp,
-         .force_linear_sample_interp = key->ps.part.prolog.force_linear_sample_interp,
          .force_persp_center_interp = key->ps.part.prolog.force_persp_center_interp,
          .force_linear_center_interp = key->ps.part.prolog.force_linear_center_interp,
          .interpolate_at_sample_force_center = key->ps.mono.interpolate_at_sample_force_center,
          .load_sample_positions_always_loads_current_ones = true,
          .force_front_face = key->ps.opt.force_front_face_input,
-         .ps_iter_samples = 1 << key->ps.part.prolog.samplemask_log_ps_iter,
+         /* This forces per-sample interpolation (if at least 2) and lowers sample_mask_in. */
+         .ps_iter_samples = key->ps.part.prolog.samplemask_log_ps_iter ?
+                              (1 << key->ps.part.prolog.samplemask_log_ps_iter) :
+                              (key->ps.part.prolog.force_persp_sample_interp ||
+                               key->ps.part.prolog.force_linear_sample_interp ? 2 : 1),
 
          .fbfetch_is_1D = key->ps.mono.fbfetch_is_1D,
          .fbfetch_layered = key->ps.mono.fbfetch_layered,