[PATCH] drm/i915: fix cursor handling when runtime suspended

[Paulo Zanoni <przanoni@gmail.com>]

From: Paulo Zanoni <paulo.r.zanoni@intel.com>

If we're runtime suspended and try to use the cursor interfaces, we
will get a lot of WARNs saying we did the wrong thing.

For intel_crtc_update_cursor(), all we need to do is return if the
CRTC is not active, since writing the registers won't really have any
effect if the screen is not visible, and we will write the registers
later when enabling the screen.

For intel_crtc_cursor_set_obj(), we just get the proper power domain
reference, since this function does a lot of stuff.

Testcase: igt/pm_rpm/cursor
Testcase: igt/pm_rpm/cursor-dpms
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=81645
Cc: stable@vger.kernel.org
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index d1e9570..c8f36b0 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8151,6 +8151,9 @@ static void intel_crtc_update_cursor(struct drm_crtc *crtc,
 	if (base == 0 && intel_crtc->cursor_base == 0)
 		return;
 
+	if (!intel_crtc->active)
+		return;
+
 	I915_WRITE(CURPOS(pipe), pos);
 
 	if (IS_IVYBRIDGE(dev) || IS_HASWELL(dev) || IS_BROADWELL(dev))
@@ -8181,6 +8184,8 @@ static int intel_crtc_cursor_set_obj(struct drm_crtc *crtc,
 	uint32_t addr;
 	int ret;
 
+	intel_display_power_get(dev_priv, POWER_DOMAIN_PIPE(pipe));
+
 	/* if we want to turn off the cursor ignore width and height */
 	if (!obj) {
 		DRM_DEBUG_KMS("cursor off\n");
@@ -8195,13 +8200,14 @@ static int intel_crtc_cursor_set_obj(struct drm_crtc *crtc,
 			(width == 128 && height == 128 && !IS_GEN2(dev)) ||
 			(width == 256 && height == 256 && !IS_GEN2(dev)))) {
 		DRM_DEBUG("Cursor dimension not supported\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto fail;
 	}
 
 	if (obj->base.size < width * height * 4) {
 		DRM_DEBUG_KMS("buffer is too small\n");
 		ret = -ENOMEM;
-		goto fail;
+		goto fail_unref;
 	}
 
 	/* we only need to pin inside GTT if cursor is non-phy */
@@ -8275,13 +8281,16 @@ static int intel_crtc_cursor_set_obj(struct drm_crtc *crtc,
 
 	intel_frontbuffer_flip(dev, INTEL_FRONTBUFFER_CURSOR(pipe));
 
+	intel_display_power_put(dev_priv, POWER_DOMAIN_PIPE(pipe));
 	return 0;
 fail_unpin:
 	i915_gem_object_unpin_from_display_plane(obj);
 fail_locked:
 	mutex_unlock(&dev->struct_mutex);
-fail:
+fail_unref:
 	drm_gem_object_unreference_unlocked(&obj->base);
+fail:
+	intel_display_power_put(dev_priv, POWER_DOMAIN_PIPE(pipe));
 	return ret;
 }
 
-- 
2.0.1