drm/i915: Move vblank enable earlier and disable later

We changed to an interrupt based vblank wait (as opposed to polling)
in:
 commit 44bd93a3d367913d883be6abba9a6e51a53c4e90
 Author: Daniel Vetter <daniel.vetter@ffwll.ch>
 Date:   Fri Jul 25 23:36:44 2014 +0200

    drm/i915: Use generic vblank wait

However we already had vblank waits on the wrong side of
drm_vblank_{on,off}() calls due to various workarounds, so now we get
a warning more or less every time we do a modeset, and we fail to
wait for the vblank like we should.

Move the drm_vblank_{on,off}() calls back out from
intel_crtc_{enable,disable}_planes() so that all of these vblank waits
return to proper operation. Also move the cxsr wait a bit earlier so
that we can keep the encoder disable after we've turned off vblanks.
Moving stuff out from the plane enable/disable functions seems
preferrable to moving the workaround stuff in since the workarounds are
required only on specific platforms.

While at it switch over to the drm_crtc_ variants of the vblank on/off
functions.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=82525
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=82490
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -3997,10 +3997,6 @@ static void intel_crtc_enable_planes(struct drm_crtc *crtc)
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	int pipe = intel_crtc->pipe;
 
-	assert_vblank_disabled(crtc);
-
-	drm_vblank_on(dev, pipe);
-
 	intel_enable_primary_hw_plane(crtc->primary, crtc);
 	intel_enable_planes(crtc);
 	intel_crtc_update_cursor(crtc, true);
@@ -4046,10 +4042,6 @@ static void intel_crtc_disable_planes(struct drm_crtc *crtc)
 	 * consider this a flip to a NULL plane.
 	 */
 	intel_frontbuffer_flip(dev, INTEL_FRONTBUFFER_ALL_MASK(pipe));
-
-	drm_vblank_off(dev, pipe);
-
-	assert_vblank_disabled(crtc);
 }
 
 static void ironlake_crtc_enable(struct drm_crtc *crtc)
@@ -4119,6 +4111,9 @@ static void ironlake_crtc_enable(struct drm_crtc *crtc)
 	if (HAS_PCH_CPT(dev))
 		cpt_verify_modeset(dev, intel_crtc->pipe);
 
+	assert_vblank_disabled(crtc);
+	drm_crtc_vblank_on(crtc);
+
 	intel_crtc_enable_planes(crtc);
 }
 
@@ -4226,6 +4221,9 @@ static void haswell_crtc_enable(struct drm_crtc *crtc)
 		intel_opregion_notify_encoder(encoder, true);
 	}
 
+	assert_vblank_disabled(crtc);
+	drm_crtc_vblank_on(crtc);
+
 	/* If we change the relative order between pipe/planes enabling, we need
 	 * to change the workaround. */
 	haswell_mode_set_planes_workaround(intel_crtc);
@@ -4261,6 +4259,9 @@ static void ironlake_crtc_disable(struct drm_crtc *crtc)
 
 	intel_crtc_disable_planes(crtc);
 
+	drm_crtc_vblank_off(crtc);
+	assert_vblank_disabled(crtc);
+
 	for_each_encoder_on_crtc(dev, crtc, encoder)
 		encoder->disable(encoder);
 
@@ -4323,6 +4324,9 @@ static void haswell_crtc_disable(struct drm_crtc *crtc)
 
 	intel_crtc_disable_planes(crtc);
 
+	drm_crtc_vblank_off(crtc);
+	assert_vblank_disabled(crtc);
+
 	for_each_encoder_on_crtc(dev, crtc, encoder) {
 		intel_opregion_notify_encoder(encoder, false);
 		encoder->disable(encoder);
@@ -4789,6 +4793,9 @@ static void valleyview_crtc_enable(struct drm_crtc *crtc)
 	for_each_encoder_on_crtc(dev, crtc, encoder)
 		encoder->enable(encoder);
 
+	assert_vblank_disabled(crtc);
+	drm_crtc_vblank_on(crtc);
+
 	intel_crtc_enable_planes(crtc);
 
 	/* Underruns don't raise interrupts, so check manually. */
@@ -4846,6 +4853,9 @@ static void i9xx_crtc_enable(struct drm_crtc *crtc)
 	for_each_encoder_on_crtc(dev, crtc, encoder)
 		encoder->enable(encoder);
 
+	assert_vblank_disabled(crtc);
+	drm_crtc_vblank_on(crtc);
+
 	intel_crtc_enable_planes(crtc);
 
 	/*
@@ -4909,9 +4919,6 @@ static void i9xx_crtc_disable(struct drm_crtc *crtc)
 	intel_set_memory_cxsr(dev_priv, false);
 	intel_crtc_disable_planes(crtc);
 
-	for_each_encoder_on_crtc(dev, crtc, encoder)
-		encoder->disable(encoder);
-
 	/*
 	 * On gen2 planes are double buffered but the pipe isn't, so we must
 	 * wait for planes to fully turn off before disabling the pipe.
@@ -4920,6 +4927,12 @@ static void i9xx_crtc_disable(struct drm_crtc *crtc)
 	 */
 	intel_wait_for_vblank(dev, pipe);
 
+	drm_crtc_vblank_off(crtc);
+	assert_vblank_disabled(crtc);
+
+	for_each_encoder_on_crtc(dev, crtc, encoder)
+		encoder->disable(encoder);
+
 	intel_disable_pipe(intel_crtc);
 
 	i9xx_pfit_disable(intel_crtc);