drm/i915: fix plane/cursor handling when runtime suspended

pzanoni-intel · jnikula · commit d6dd6843ff4a · 2014-08-26T14:55:53.000+03:00
If we're runtime suspended and try to use the plane interfaces, we will get a lot of WARNs saying we did the wrong thing. We need to get runtime PM references to pin the objects, and to change the fences. The pin functions are the ideal places for this, but intel_crtc_cursor_set_obj() doesn't call them, so we also have to add get/put calls inside it. There is no problem if we runtime suspend right after these functions are finished, because the registers written are forwarded to system memory. Note: for a complete fix of the cursor-dpms test case, we also need the patch named "drm/i915: Don't try to enable cursor from setplane when crtc is disabled". v2: - Narrow the put/get calls on intel_crtc_cursor_set_obj() (Daniel) v3: - Make get/put also surround the fence and unpin calls (Daniel and Ville). - Merge all the plane changes into a single patch since they're the same fix. - Add the comment requested by Daniel. v4: - Remove spurious whitespace (Ville). v5: - Remove intel_crtc_update_cursor() chunk since Ville did an equivalent fix in another patch (Ville). v6: - Remove unpin chunk: it will be on a separate patch (Ville, Chris, Daniel). v7: - Same thing, new color. Testcase: igt/pm_rpm/cursor Testcase: igt/pm_rpm/cursor-dpms Testcase: igt/pm_rpm/legacy-planes Testcase: igt/pm_rpm/legacy-planes-dpms Testcase: igt/pm_rpm/universal-planes Testcase: igt/pm_rpm/universal-planes-dpms Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=81645 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=82603 Cc: stable@vger.kernel.org Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
@@ -2233,6 +2233,15 @@ intel_pin_and_fence_fb_obj(struct drm_device *dev,
 	if (need_vtd_wa(dev) && alignment < 256 * 1024)
 		alignment = 256 * 1024;
 
+	/*
+	 * Global gtt pte registers are special registers which actually forward
+	 * writes to a chunk of system memory. Which means that there is no risk
+	 * that the register values disappear as soon as we call
+	 * intel_runtime_pm_put(), so it is correct to wrap only the
+	 * pin/unpin/fence and not more.
+	 */
+	intel_runtime_pm_get(dev_priv);
+
 	dev_priv->mm.interruptible = false;
 	ret = i915_gem_object_pin_to_display_plane(obj, alignment, pipelined);
 	if (ret)
@@ -2250,12 +2259,14 @@ intel_pin_and_fence_fb_obj(struct drm_device *dev,
 	i915_gem_object_pin_fence(obj);
 
 	dev_priv->mm.interruptible = true;
+	intel_runtime_pm_put(dev_priv);
 	return 0;
 
 err_unpin:
 	i915_gem_object_unpin_from_display_plane(obj);
 err_interruptible:
 	dev_priv->mm.interruptible = true;
+	intel_runtime_pm_put(dev_priv);
 	return ret;
 }
 
@@ -8240,6 +8251,15 @@ static int intel_crtc_cursor_set_obj(struct drm_crtc *crtc,
 			goto fail_locked;
 		}
 
+		/*
+		 * Global gtt pte registers are special registers which actually
+		 * forward writes to a chunk of system memory. Which means that
+		 * there is no risk that the register values disappear as soon
+		 * as we call intel_runtime_pm_put(), so it is correct to wrap
+		 * only the pin/unpin/fence and not more.
+		 */
+		intel_runtime_pm_get(dev_priv);
+
 		/* Note that the w/a also requires 2 PTE of padding following
 		 * the bo. We currently fill all unused PTE with the shadow
 		 * page and so we should always have valid PTE following the
@@ -8252,16 +8272,20 @@ static int intel_crtc_cursor_set_obj(struct drm_crtc *crtc,
 		ret = i915_gem_object_pin_to_display_plane(obj, alignment, NULL);
 		if (ret) {
 			DRM_DEBUG_KMS("failed to move cursor bo into the GTT\n");
+			intel_runtime_pm_put(dev_priv);
 			goto fail_locked;
 		}
 
 		ret = i915_gem_object_put_fence(obj);
 		if (ret) {
 			DRM_DEBUG_KMS("failed to release fence for cursor");
+			intel_runtime_pm_put(dev_priv);
 			goto fail_unpin;
 		}
 
 		addr = i915_gem_obj_ggtt_offset(obj);
+
+		intel_runtime_pm_put(dev_priv);
 	} else {
 		int align = IS_I830(dev) ? 16 * 1024 : 256;
 		ret = i915_gem_object_attach_phys(obj, align);
