From 45205cc5d743cc9cb4335b441f5edd0fb1a8f6b1 Mon Sep 17 00:00:00 2001
From: Themaister <maister@archlinux.us>
Date: Sun, 13 Jul 2014 19:23:08 +0200
Subject: [PATCH] When modechanging on X11, try to match configured refresh
 rate.

---
 gfx/context/drm_egl_ctx.c | 15 ++++-----------
 gfx/context/x11_common.c  | 15 ++++++++++++---
 2 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/gfx/context/drm_egl_ctx.c b/gfx/context/drm_egl_ctx.c
index f48ca94647..b3ee18eebe 100644
--- a/gfx/context/drm_egl_ctx.c
+++ b/gfx/context/drm_egl_ctx.c
@@ -34,6 +34,7 @@
 #include <unistd.h>
 #include <sched.h>
 #include <sys/time.h>
+#include <math.h>
 
 #include <EGL/egl.h>
 #include <EGL/eglext.h>
@@ -599,19 +600,11 @@ static bool gfx_ctx_set_video_mode(void *data,
          if (width != g_connector->modes[i].hdisplay || height != g_connector->modes[i].vdisplay)
             continue;
 
-         if (!g_drm_mode)
+         float diff = fabsf(g_connector->modes[i].vrefresh - g_settings.video.refresh_rate);
+         if (!g_drm_mode || diff < minimum_fps_diff)
          {
             g_drm_mode = &g_connector->modes[i];
-            minimum_fps_diff = g_drm_mode->vrefresh - g_settings.video.refresh_rate;
-         }
-         else
-         {
-            float diff = g_connector->modes[i].vrefresh - g_settings.video.refresh_rate;
-            if (diff < minimum_fps_diff)
-            {
-               g_drm_mode = &g_connector->modes[i];
-               minimum_fps_diff = diff;
-            }
+            minimum_fps_diff = diff;
          }
       }
    }
diff --git a/gfx/context/x11_common.c b/gfx/context/x11_common.c
index e492c2320b..79be9810ca 100644
--- a/gfx/context/x11_common.c
+++ b/gfx/context/x11_common.c
@@ -18,6 +18,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <X11/Xatom.h>
+#include <math.h>
 #include "../image/image.h"
 #include "../../general.h"
 #include "../../input/input_common.h"
@@ -146,13 +147,21 @@ static bool get_video_mode(Display *dpy, unsigned width, unsigned height, XF86Vi
    *desktop_mode = *modes[0];
 
    bool ret = false;
+   float minimum_fps_diff = 0.0f;
+
    for (i = 0; i < num_modes; i++)
    {
-      if (modes[i]->hdisplay == width && modes[i]->vdisplay == height)
+      const XF86VidModeModeInfo *m = modes[i];
+      if (m->hdisplay == width && m->vdisplay == height)
       {
-         *mode = *modes[i];
+         float refresh = m->dotclock * 1000.0f / (m->htotal * m->vtotal);
+         float diff = fabsf(refresh - g_settings.video.refresh_rate);
+         if (!ret || diff < minimum_fps_diff)
+         {
+            *mode = *m;
+            minimum_fps_diff = diff;
+         }
          ret = true;
-         break;
       }
    }