[mutter/benzea/gamma-fix-3.36: 2/2] kms/crtc: Always consider gamma state valid

[Benjamin Berg <bberg src gnome org>]

commit 785007588bada06b464d405e1b2e9533d0e7f53c
Author: Benjamin Berg <bberg redhat com>
Date:   Mon Sep 7 16:15:30 2020 +0200

    kms/crtc: Always consider gamma state valid
    
    The gamma curve remains valid even if the CRTC is turned off. As such,
    there is no need to clear it and doing so breaks reading the gamma curve
    while the screens are turned off using DPMS.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1419
    
    Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1392

 src/backends/native/meta-kms-crtc.c | 32 --------------------------------
 1 file changed, 32 deletions(-)
---
diff --git a/src/backends/native/meta-kms-crtc.c b/src/backends/native/meta-kms-crtc.c
index f5547567b8..ebdd8ed9d5 100644
--- a/src/backends/native/meta-kms-crtc.c
+++ b/src/backends/native/meta-kms-crtc.c
@@ -156,13 +156,10 @@ void
 meta_kms_crtc_predict_state (MetaKmsCrtc   *crtc,
                              MetaKmsUpdate *update)
 {
-  gboolean is_gamma_valid;
   GList *mode_sets;
   GList *crtc_gammas;
   GList *l;
 
-  is_gamma_valid = TRUE;
-
   mode_sets = meta_kms_update_get_mode_sets (update);
   for (l = mode_sets; l; l = l->next)
     {
@@ -190,8 +187,6 @@ meta_kms_crtc_predict_state (MetaKmsCrtc   *crtc,
           crtc->current_state.drm_mode = (drmModeModeInfo) { 0 };
         }
 
-      is_gamma_valid = FALSE;
-
       break;
     }
 
@@ -212,35 +207,8 @@ meta_kms_crtc_predict_state (MetaKmsCrtc   *crtc,
       crtc->current_state.gamma.blue =
         g_memdup (gamma->blue, gamma->size * sizeof (uint16_t));
 
-      is_gamma_valid = TRUE;
       break;
     }
-
-  if (!is_gamma_valid)
-    {
-      if (crtc->current_state.is_drm_mode_valid)
-        {
-          MetaKmsImplDevice *impl_device;
-          drmModeCrtc *drm_crtc;
-
-          impl_device = meta_kms_device_get_impl_device (crtc->device);
-          drm_crtc = drmModeGetCrtc (meta_kms_impl_device_get_fd (impl_device),
-                                     crtc->id);
-          if (drm_crtc)
-            {
-              read_gamma_state (crtc, impl_device, drm_crtc);
-              drmModeFreeCrtc (drm_crtc);
-            }
-          else
-            {
-              clear_gamma_state (crtc);
-            }
-        }
-      else
-        {
-          clear_gamma_state (crtc);
-        }
-    }
 }
 
 MetaKmsCrtc *