drm/i915/lvds: Ensure panel is unlocked for Ironlake or the panel fitter

Commit 77d07fd9d73ef28689737c0952dbd5d6a5017743 introduced a regression
where by not waiting for the panel to be turned off, left the panel and
PLL registers locked across the modeset. Thus the panel remaining blank.

As pointed out by Daniel Vetter, when testing LVDS it helps to open the
laptop and look at the actual panel you are purporting to test.

A second issue with the patch was that in order to modify the panel
fitter before gen5, the pipe and the panel must have be completely
powered down. So we wait.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 0 insertions, 31 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 594f8f2410ab..0004534e7c7d 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2636,33 +2636,6 @@ static int i830_get_display_clock_speed(struct drm_device *dev)
 	return 133000;
 }
 
-/**
- * Return the pipe currently connected to the panel fitter,
- * or -1 if the panel fitter is not present or not in use
- */
-int intel_panel_fitter_pipe (struct drm_device *dev)
-{
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	u32  pfit_control;
-
-	/* i830 doesn't have a panel fitter */
-	if (IS_I830(dev))
-		return -1;
-
-	pfit_control = I915_READ(PFIT_CONTROL);
-
-	/* See if the panel fitter is in use */
-	if ((pfit_control & PFIT_ENABLE) == 0)
-		return -1;
-
-	/* 965 can place panel fitter on either pipe */
-	if (IS_I965G(dev))
-		return (pfit_control >> 29) & 0x3;
-
-	/* older chips can only use pipe 1 */
-	return 1;
-}
-
 struct fdi_m_n {
 	u32        tu;
 	u32        gmch_m;
@@ -3921,10 +3894,6 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
 	pipeconf |= PIPECONF_ENABLE;
 	dpll |= DPLL_VCO_ENABLE;
 
-	/* Disable the panel fitter if it was on our pipe */
-	if (!HAS_PCH_SPLIT(dev) && intel_panel_fitter_pipe(dev) == pipe)
-		I915_WRITE(PFIT_CONTROL, 0);
-
 	DRM_DEBUG_KMS("Mode for pipe %c:\n", pipe == 0 ? 'A' : 'B');
 	drm_mode_debug_printmodeline(mode);