[Intel-gfx] [PATCH v4 8/9] drm/i915: Nuke FBC from SW_FINISH ioctl

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

FBC host modification tracking only works through GTT mmaps, so any
direct CPU access needs to manually nuke the compressed framebuffer
on modifications. Do the nuking from the SW_FINISH ioctl.

v2: nuke from SW_FINISH insted of DIRTYFB ioctl
v3: Call intel_fbc_nuke() only when pin_display is true
v4: Don't oops if dev_priv->fbc.fb is NULL

Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_gem.c  |  4 +++-
 drivers/gpu/drm/i915/intel_drv.h |  1 +
 drivers/gpu/drm/i915/intel_pm.c  | 33 +++++++++++++++++++++++++++++++++
 3 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 0ecc735..b5395aa 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1306,8 +1306,10 @@ i915_gem_sw_finish_ioctl(struct drm_device *dev, void *data,
 	}
 
 	/* Pinned buffers may be scanout, so flush the cache */
-	if (obj->pin_display)
+	if (obj->pin_display) {
 		i915_gem_object_flush_cpu_write_domain(obj, true);
+		intel_fbc_nuke(obj);
+	}
 
 	drm_gem_object_unreference(&obj->base);
 unlock:
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 2fa843f..2baf0dd 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -836,6 +836,7 @@ void intel_update_sprite_watermarks(struct drm_plane *plane,
 				    bool enabled, bool scaled);
 void intel_init_pm(struct drm_device *dev);
 bool intel_fbc_enabled(struct drm_device *dev);
+void intel_fbc_nuke(struct drm_i915_gem_object *obj);
 void intel_update_fbc(struct drm_device *dev);
 void intel_gpu_ips_init(struct drm_i915_private *dev_priv);
 void intel_gpu_ips_teardown(void);
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 4f274ca..f46bc36 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -418,6 +418,39 @@ void intel_disable_fbc(struct drm_device *dev)
 	}
 }
 
+void intel_fbc_nuke(struct drm_i915_gem_object *obj)
+{
+	struct drm_device *dev = obj->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct drm_crtc *crtc;
+
+	if (dev_priv->fbc.fbc_work) {
+		if (to_intel_framebuffer(dev_priv->fbc.fbc_work->fb)->obj != obj)
+			return;
+
+		crtc = dev_priv->fbc.fbc_work->crtc;
+	} else {
+		if (!dev_priv->fbc.fb)
+			return;
+
+		if (to_intel_framebuffer(dev_priv->fbc.fb)->obj != obj)
+			return;
+
+		if (WARN_ON(dev_priv->fbc.plane < 0))
+			return;
+
+		crtc = dev_priv->plane_to_crtc_mapping[dev_priv->fbc.plane];
+	}
+
+	intel_disable_fbc(dev);
+
+	/*
+	 * Must wait until the next vblank before re-enabling
+	 * otherwise the nuking won't actually happen.
+	 */
+	intel_enable_fbc(crtc, 500);
+}
+
 static bool set_no_fbc_reason(struct drm_i915_private *dev_priv,
 			      enum no_fbc_reason reason)
 {
-- 
1.8.3.2