drm/i915/tv: Rip out pipe-disabling nonsense from ->mode_set

The pipe and plane _are_ disabled when we call this. So replace it
all with the corresponding assert (as self-documenting code) and
rip out all the lore.

Checking for a disabled plane would require us to export those macros
from intel_display.c, but if the pipe is off the plane isn't working
either. So this single check is good enough.
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_tv.c

@@ -1026,7 +1026,8 @@ static void intel_tv_mode_set(struct intel_encoder *encoder)
 	const struct video_levels *video_levels;
 	const struct color_conversion *color_conversion;
 	bool burst_ena;
-	int pipe = intel_crtc->pipe;
+	int xpos = 0x0, ypos = 0x0;
+	unsigned int xsize, ysize;
 
 	if (!tv_mode)
 		return;	/* can't happen (mode_prepare prevents this) */
@@ -1110,24 +1111,8 @@ static void intel_tv_mode_set(struct intel_encoder *encoder)
 		I915_WRITE(TV_CLR_LEVEL,
 			   ((video_levels->black << TV_BLACK_LEVEL_SHIFT) |
 			    (video_levels->blank << TV_BLANK_LEVEL_SHIFT)));
-	{
-		int pipeconf_reg = PIPECONF(pipe);
-		int dspcntr_reg = DSPCNTR(intel_crtc->plane);
-		int pipeconf = I915_READ(pipeconf_reg);
-		int dspcntr = I915_READ(dspcntr_reg);
-		int xpos = 0x0, ypos = 0x0;
-		unsigned int xsize, ysize;
-		/* Pipe must be off here */
-		I915_WRITE(dspcntr_reg, dspcntr & ~DISPLAY_PLANE_ENABLE);
-		intel_flush_primary_plane(dev_priv, intel_crtc->plane);
-
-		/* Wait for vblank for the disable to take effect */
-		if (IS_GEN2(dev))
-			intel_wait_for_vblank(dev, intel_crtc->pipe);
 
-		I915_WRITE(pipeconf_reg, pipeconf & ~PIPECONF_ENABLE);
-		/* Wait for vblank for the disable to take effect. */
-		intel_wait_for_pipe_off(dev, intel_crtc->pipe);
+	assert_pipe_disabled(dev_priv, intel_crtc->pipe);
 
 	/* Filter ctl must be set before TV_WIN_SIZE */
 	I915_WRITE(TV_FILTER_CTL_1, TV_AUTO_SCALE);
@@ -1146,11 +1131,6 @@ static void intel_tv_mode_set(struct intel_encoder *encoder)
 	I915_WRITE(TV_WIN_POS, (xpos<<16)|ypos);
 	I915_WRITE(TV_WIN_SIZE, (xsize<<16)|ysize);
 
-		I915_WRITE(pipeconf_reg, pipeconf);
-		I915_WRITE(dspcntr_reg, dspcntr);
-		intel_flush_primary_plane(dev_priv, intel_crtc->plane);
-	}
-
 	j = 0;
 	for (i = 0; i < 60; i++)
 		I915_WRITE(TV_H_LUMA_0 + (i<<2), tv_mode->filter_table[j++]);