drm/i915: restore render clock gating on resume

Rather than restoring just a few clock gating registers on resume,
just reinitialize the whole thing.

Signed-off-by: Andy Lutomirski <luto@mit.edu>
[anholt: Fixed up for RC6 support landed since the patch was written]
Signed-off-by: Eric Anholt <eric@anholt.net>

4 files changed, 22 insertions, 23 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e28d6c9a0ae9..1d6171087298 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -381,8 +381,6 @@ typedef struct drm_i915_private {
         u32 saveFDI_RXA_IMR;
         u32 saveFDI_RXB_IMR;
         u32 saveCACHE_MODE_0;
-        u32 saveD_STATE;
-        u32 saveDSPCLK_GATE_D;
         u32 saveMI_ARB_STATE;
         u32 saveSWF0[16];
         u32 saveSWF1[16];
diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c
index 402a7eb2922c..00f6d97c7cc5 100644
--- a/drivers/gpu/drm/i915/i915_suspend.c
+++ b/drivers/gpu/drm/i915/i915_suspend.c
@@ -722,10 +722,6 @@ int i915_save_state(struct drm_device *dev)
                 dev_priv->saveIMR = I915_READ(IMR);
         }
 
-        /* Clock gating state */
-        dev_priv->saveD_STATE = I915_READ(D_STATE);
-        dev_priv->saveDSPCLK_GATE_D = I915_READ(DSPCLK_GATE_D); /* Not sure about this */
-
         /* Cache mode state */
         dev_priv->saveCACHE_MODE_0 = I915_READ(CACHE_MODE_0);
 
@@ -800,8 +796,7 @@ int i915_restore_state(struct drm_device *dev)
         }
 
         /* Clock gating state */
-        I915_WRITE (D_STATE, dev_priv->saveD_STATE);
-        I915_WRITE (DSPCLK_GATE_D, dev_priv->saveDSPCLK_GATE_D);
+        intel_init_clock_gating(dev);
 
         /* Cache mode state */
         I915_WRITE (CACHE_MODE_0, dev_priv->saveCACHE_MODE_0 | 0xffff0000);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 902cc5386f19..279dc96e3eb2 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4584,28 +4584,33 @@ void intel_init_clock_gating(struct drm_device *dev)
                 struct drm_i915_gem_object *obj_priv;
                 int ret;
 
-                pwrctx = drm_gem_object_alloc(dev, 4096);
-                if (!pwrctx) {
-                        DRM_DEBUG("failed to alloc power context, RC6 disabled\n");
-                        goto out;
-                }
+                if (dev_priv->pwrctx) {
+                        obj_priv = dev_priv->pwrctx->driver_private;
+                } else {
+                        pwrctx = drm_gem_object_alloc(dev, 4096);
+                        if (!pwrctx) {
+                                DRM_DEBUG("failed to alloc power context, "
+                                          "RC6 disabled\n");
+                                goto out;
+                        }
 
-                ret = i915_gem_object_pin(pwrctx, 4096);
-                if (ret) {
-                        DRM_ERROR("failed to pin power context: %d\n", ret);
-                        drm_gem_object_unreference(pwrctx);
-                        goto out;
-                }
+                        ret = i915_gem_object_pin(pwrctx, 4096);
+                        if (ret) {
+                                DRM_ERROR("failed to pin power context: %d\n",
+                                          ret);
+                                drm_gem_object_unreference(pwrctx);
+                                goto out;
+                        }
 
-                i915_gem_object_set_to_gtt_domain(pwrctx, 1);
+                        i915_gem_object_set_to_gtt_domain(pwrctx, 1);
 
-                obj_priv = pwrctx->driver_private;
+                        dev_priv->pwrctx = pwrctx;
+                        obj_priv = pwrctx->driver_private;
+                }
 
                 I915_WRITE(PWRCTXA, obj_priv->gtt_offset | PWRCTX_EN);
                 I915_WRITE(MCHBAR_RENDER_STANDBY,
                            I915_READ(MCHBAR_RENDER_STANDBY) & ~RCX_SW_EXIT);
-
-                dev_priv->pwrctx = pwrctx;
         }
 
 out:
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 9ffa31e13eb3..a51573da1ff6 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -208,6 +208,7 @@ extern void intel_crtc_fb_gamma_set(struct drm_crtc *crtc, u16 red, u16 green,
                                     u16 blue, int regno);
 extern void intel_crtc_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
                                     u16 *blue, int regno);
+extern void intel_init_clock_gating(struct drm_device *dev);
 
 extern int intel_framebuffer_create(struct drm_device *dev,
                                     struct drm_mode_fb_cmd *mode_cmd,