diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
index 2761b0bb2d6..ba0b7f09d7d 100644
--- a/src/mesa/state_tracker/st_extensions.c
+++ b/src/mesa/state_tracker/st_extensions.c
@@ -704,17 +704,19 @@ get_max_samples_for_formats(struct pipe_screen *screen,
                             unsigned max_samples,
                             unsigned bind)
 {
-   unsigned i, f;
+   unsigned i, f, supported_samples = 0;
 
-   for (i = max_samples; i > 0; --i) {
-      for (f = 0; f < num_formats; f++) {
+   for (f = 0; f < num_formats; f++) {
+      for (i = max_samples; i > 0; --i) {
          if (screen->is_format_supported(screen, formats[f],
                                          PIPE_TEXTURE_2D, i, i, bind)) {
-            return i;
+            /* update both return value and loop-boundary */
+            max_samples = supported_samples = i;
+            break;
          }
       }
    }
-   return 0;
+   return supported_samples;
 }
 
 static unsigned
@@ -1352,6 +1354,10 @@ void st_init_extensions(struct pipe_screen *screen,
    /* Maximum sample count. */
    {
       static const enum pipe_format color_formats[] = {
+         PIPE_FORMAT_R32G32B32A32_FLOAT,
+         PIPE_FORMAT_R32G32B32A32_UNORM,
+         PIPE_FORMAT_R16G16B16A16_FLOAT,
+         PIPE_FORMAT_R16G16B16A16_UNORM,
          PIPE_FORMAT_R8G8B8A8_UNORM,
          PIPE_FORMAT_B8G8R8A8_UNORM,
          PIPE_FORMAT_A8R8G8B8_UNORM,
@@ -1365,6 +1371,8 @@ void st_init_extensions(struct pipe_screen *screen,
          PIPE_FORMAT_Z32_FLOAT
       };
       static const enum pipe_format int_formats[] = {
+         PIPE_FORMAT_R32G32B32A32_SINT,
+         PIPE_FORMAT_R16G16B16A16_SINT,
          PIPE_FORMAT_R8G8B8A8_SINT
       };
       static const enum pipe_format void_formats[] = {