diff --git a/docs/relnotes/19.2.0.html b/docs/relnotes/19.2.0.html
index 20eb8d3d04f..2d1c39a81af 100644
--- a/docs/relnotes/19.2.0.html
+++ b/docs/relnotes/19.2.0.html
@@ -40,6 +40,7 @@ TBD.
 
 <ul>
 <li>GL_ARB_post_depth_coverage on radeonsi (Navi)</li>
+<li>GL_EXT_shader_samples_identical on iris and radeonsi (if using NIR)</li>
 <li>EGL_EXT_platform_device</li>
 <li>VK_EXT_queue_family_foreign for radv</li>
 <li>VK_EXT_shader_demote_to_helper_invocation on Intel.</li>
diff --git a/src/gallium/auxiliary/util/u_screen.c b/src/gallium/auxiliary/util/u_screen.c
index fec4a10c539..270d13a5056 100644
--- a/src/gallium/auxiliary/util/u_screen.c
+++ b/src/gallium/auxiliary/util/u_screen.c
@@ -335,6 +335,7 @@ u_pipe_screen_get_param_defaults(struct pipe_screen *pscreen,
    case PIPE_CAP_FRAGMENT_SHADER_INTERLOCK:
    case PIPE_CAP_CS_DERIVED_SYSTEM_VALUES_SUPPORTED:
    case PIPE_CAP_ATOMIC_FLOAT_MINMAX:
+   case PIPE_CAP_SHADER_SAMPLES_IDENTICAL:
       return 0;
 
    case PIPE_CAP_MAX_GS_INVOCATIONS:
diff --git a/src/gallium/docs/source/screen.rst b/src/gallium/docs/source/screen.rst
index 065eb8fd2f1..3a1bb3e02ec 100644
--- a/src/gallium/docs/source/screen.rst
+++ b/src/gallium/docs/source/screen.rst
@@ -546,6 +546,7 @@ The integer capabilities:
   modifiers in the vertex shader.
 * ``PIPE_CAP_TEXTURE_SHADOW_LOD``: True if the driver supports shadow sampler
   types with texture functions having interaction with LOD of texture lookup.
+* ``PIPE_CAP_SHADER_SAMPLES_IDENTICAL``: True if the driver supports a shader query to tell whether all samples of a multisampled surface are definitely identical.
 
 .. _pipe_capf:
 
diff --git a/src/gallium/drivers/iris/iris_screen.c b/src/gallium/drivers/iris/iris_screen.c
index 9aea9e963c2..09232896701 100644
--- a/src/gallium/drivers/iris/iris_screen.c
+++ b/src/gallium/drivers/iris/iris_screen.c
@@ -198,6 +198,7 @@ iris_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_SURFACE_REINTERPRET_BLOCKS:
    case PIPE_CAP_CS_DERIVED_SYSTEM_VALUES_SUPPORTED:
    case PIPE_CAP_TEXTURE_SHADOW_LOD:
+   case PIPE_CAP_SHADER_SAMPLES_IDENTICAL:
       return true;
    case PIPE_CAP_FBFETCH:
       /* TODO: Support non-coherent FB fetch on Broadwell */
diff --git a/src/gallium/drivers/radeonsi/si_get.c b/src/gallium/drivers/radeonsi/si_get.c
index 85807db0e1c..15777392555 100644
--- a/src/gallium/drivers/radeonsi/si_get.c
+++ b/src/gallium/drivers/radeonsi/si_get.c
@@ -214,6 +214,7 @@ static int si_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
 				RADEON_SPARSE_PAGE_SIZE : 0;
 
 	case PIPE_CAP_PACKED_UNIFORMS:
+	case PIPE_CAP_SHADER_SAMPLES_IDENTICAL:
 		if (sscreen->options.enable_nir)
 			return 1;
 		return 0;
diff --git a/src/gallium/include/pipe/p_defines.h b/src/gallium/include/pipe/p_defines.h
index c706f9819f8..9662cf63b82 100644
--- a/src/gallium/include/pipe/p_defines.h
+++ b/src/gallium/include/pipe/p_defines.h
@@ -895,6 +895,7 @@ enum pipe_cap
    PIPE_CAP_FRAGMENT_SHADER_DERIVATIVES,
    PIPE_CAP_VERTEX_SHADER_SATURATE,
    PIPE_CAP_TEXTURE_SHADOW_LOD,
+   PIPE_CAP_SHADER_SAMPLES_IDENTICAL,
 };
 
 /**
diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
index 72a6d843ae9..c146c8d9902 100644
--- a/src/mesa/state_tracker/st_extensions.c
+++ b/src/mesa/state_tracker/st_extensions.c
@@ -752,6 +752,7 @@ void st_init_extensions(struct pipe_screen *screen,
       { o(EXT_multisampled_render_to_texture), PIPE_CAP_SURFACE_SAMPLE_COUNT           },
       { o(EXT_semaphore),                    PIPE_CAP_FENCE_SIGNAL                     },
       { o(EXT_semaphore_fd),                 PIPE_CAP_FENCE_SIGNAL                     },
+      { o(EXT_shader_samples_identical),     PIPE_CAP_SHADER_SAMPLES_IDENTICAL         },
       { o(EXT_texture_array),                PIPE_CAP_MAX_TEXTURE_ARRAY_LAYERS         },
       { o(EXT_texture_filter_anisotropic),   PIPE_CAP_ANISOTROPIC_FILTER               },
       { o(EXT_texture_mirror_clamp),         PIPE_CAP_TEXTURE_MIRROR_CLAMP             },