drm/i915: Rework the FBC interval/stall stuff a bit

Don't touch DPFC_RECOMP_CTL on FBC2, use RMW to update
the FBC_CONTROL on FBC1 to make it easier for people to
experiment with different numbers. Also fix the interval
mask for FBC1.

v2: Rebased

Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 14 insertions, 20 deletions

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index d7cb6bf5712d..c68abf718825 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -88,7 +88,7 @@ static void i8xx_disable_fbc(struct drm_device *dev)
         DRM_DEBUG_KMS("disabled FBC\n");
 }
 
-static void i8xx_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
+static void i8xx_enable_fbc(struct drm_crtc *crtc)
 {
         struct drm_device *dev = crtc->dev;
         struct drm_i915_private *dev_priv = dev->dev_private;
@@ -126,11 +126,12 @@ static void i8xx_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
         }
 
         /* enable it... */
-        fbc_ctl = FBC_CTL_EN | FBC_CTL_PERIODIC;
+        fbc_ctl = I915_READ(FBC_CONTROL);
+        fbc_ctl &= 0x3fff << FBC_CTL_INTERVAL_SHIFT;
+        fbc_ctl |= FBC_CTL_EN | FBC_CTL_PERIODIC;
         if (IS_I945GM(dev))
                 fbc_ctl |= FBC_CTL_C3_IDLE; /* 945 needs special SR handling */
         fbc_ctl |= (cfb_pitch & 0xff) << FBC_CTL_STRIDE_SHIFT;
-        fbc_ctl |= (interval & 0x2fff) << FBC_CTL_INTERVAL_SHIFT;
         fbc_ctl |= obj->fence_reg;
         I915_WRITE(FBC_CONTROL, fbc_ctl);
 
@@ -145,7 +146,7 @@ static bool i8xx_fbc_enabled(struct drm_device *dev)
         return I915_READ(FBC_CONTROL) & FBC_CTL_EN;
 }
 
-static void g4x_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
+static void g4x_enable_fbc(struct drm_crtc *crtc)
 {
         struct drm_device *dev = crtc->dev;
         struct drm_i915_private *dev_priv = dev->dev_private;
@@ -154,16 +155,12 @@ static void g4x_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
         struct drm_i915_gem_object *obj = intel_fb->obj;
         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
         int plane = intel_crtc->plane == 0 ? DPFC_CTL_PLANEA : DPFC_CTL_PLANEB;
-        unsigned long stall_watermark = 200;
         u32 dpfc_ctl;
 
         dpfc_ctl = plane | DPFC_SR_EN | DPFC_CTL_LIMIT_1X;
         dpfc_ctl |= DPFC_CTL_FENCE_EN | obj->fence_reg;
         I915_WRITE(DPFC_CHICKEN, DPFC_HT_MODIFY);
 
-        I915_WRITE(DPFC_RECOMP_CTL, DPFC_RECOMP_STALL_EN |
-                   (stall_watermark << DPFC_RECOMP_STALL_WM_SHIFT) |
-                   (interval << DPFC_RECOMP_TIMER_COUNT_SHIFT));
         I915_WRITE(DPFC_FENCE_YOFF, crtc->y);
 
         /* enable it... */
@@ -219,7 +216,7 @@ static void sandybridge_blit_fbc_update(struct drm_device *dev)
         gen6_gt_force_wake_put(dev_priv, FORCEWAKE_MEDIA);
 }
 
-static void ironlake_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
+static void ironlake_enable_fbc(struct drm_crtc *crtc)
 {
         struct drm_device *dev = crtc->dev;
         struct drm_i915_private *dev_priv = dev->dev_private;
@@ -228,7 +225,6 @@ static void ironlake_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
         struct drm_i915_gem_object *obj = intel_fb->obj;
         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
         int plane = intel_crtc->plane == 0 ? DPFC_CTL_PLANEA : DPFC_CTL_PLANEB;
-        unsigned long stall_watermark = 200;
         u32 dpfc_ctl;
 
         dpfc_ctl = I915_READ(ILK_DPFC_CONTROL);
@@ -241,9 +237,6 @@ static void ironlake_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
                 dpfc_ctl |= obj->fence_reg;
         I915_WRITE(ILK_DPFC_CHICKEN, DPFC_HT_MODIFY);
 
-        I915_WRITE(ILK_DPFC_RECOMP_CTL, DPFC_RECOMP_STALL_EN |
-                   (stall_watermark << DPFC_RECOMP_STALL_WM_SHIFT) |
-                   (interval << DPFC_RECOMP_TIMER_COUNT_SHIFT));
         I915_WRITE(ILK_DPFC_FENCE_YOFF, crtc->y);
         I915_WRITE(ILK_FBC_RT_BASE, i915_gem_obj_ggtt_offset(obj) | ILK_FBC_RT_VALID);
         /* enable it... */
@@ -281,7 +274,7 @@ static bool ironlake_fbc_enabled(struct drm_device *dev)
         return I915_READ(ILK_DPFC_CONTROL) & DPFC_CTL_EN;
 }
 
-static void gen7_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
+static void gen7_enable_fbc(struct drm_crtc *crtc)
 {
         struct drm_device *dev = crtc->dev;
         struct drm_i915_private *dev_priv = dev->dev_private;
@@ -338,8 +331,7 @@ static void intel_fbc_work_fn(struct work_struct *__work)
                  * the prior work.
                  */
                 if (work->crtc->fb == work->fb) {
-                        dev_priv->display.enable_fbc(work->crtc,
-                                                     work->interval);
+                        dev_priv->display.enable_fbc(work->crtc);
 
                         dev_priv->fbc.plane = to_intel_crtc(work->crtc)->plane;
                         dev_priv->fbc.fb_id = work->crtc->fb->base.id;
@@ -376,7 +368,7 @@ static void intel_cancel_fbc_work(struct drm_i915_private *dev_priv)
         dev_priv->fbc.fbc_work = NULL;
 }
 
-static void intel_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
+static void intel_enable_fbc(struct drm_crtc *crtc)
 {
         struct intel_fbc_work *work;
         struct drm_device *dev = crtc->dev;
@@ -390,13 +382,12 @@ static void intel_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
         work = kzalloc(sizeof(*work), GFP_KERNEL);
         if (work == NULL) {
                 DRM_ERROR("Failed to allocate FBC work structure\n");
-                dev_priv->display.enable_fbc(crtc, interval);
+                dev_priv->display.enable_fbc(crtc);
                 return;
         }
 
         work->crtc = crtc;
         work->fb = crtc->fb;
-        work->interval = interval;
         INIT_DELAYED_WORK(&work->work, intel_fbc_work_fn);
 
         dev_priv->fbc.fbc_work = work;
@@ -611,7 +602,7 @@ void intel_update_fbc(struct drm_device *dev)
                 intel_disable_fbc(dev);
         }
 
-        intel_enable_fbc(crtc, 500);
+        intel_enable_fbc(crtc);
         dev_priv->fbc.no_fbc_reason = FBC_OK;
         return;
 
@@ -6073,6 +6064,9 @@ void intel_init_pm(struct drm_device *dev)
                         dev_priv->display.fbc_enabled = i8xx_fbc_enabled;
                         dev_priv->display.enable_fbc = i8xx_enable_fbc;
                         dev_priv->display.disable_fbc = i8xx_disable_fbc;
+
+                        /* This value was pulled out of someone's hat */
+                        I915_WRITE(FBC_CONTROL, 500 << FBC_CTL_INTERVAL_SHIFT);
                 }
         }