drm/i915: Leave LVDS registers unlocked

There's no reason to relock them; it just makes operations more
complex. This fixes DPMS where the panel registers were locked making
the disable not work.

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 16 insertions, 35 deletions

diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index 63188285d7f..8b521a289b2 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -400,53 +400,21 @@ out:
 
 static void intel_lvds_prepare(struct drm_encoder *encoder)
 {
-        struct drm_device *dev = encoder->dev;
-        struct drm_i915_private *dev_priv = dev->dev_private;
         struct intel_lvds *intel_lvds = to_intel_lvds(encoder);
 
-        /* We try to do the minimum that is necessary in order to unlock
-         * the registers for mode setting.
-         *
-         * On Ironlake, this is quite simple as we just set the unlock key
-         * and ignore all subtleties. (This may cause some issues...)
-         *
+        /*
          * Prior to Ironlake, we must disable the pipe if we want to adjust
          * the panel fitter. However at all other times we can just reset
          * the registers regardless.
          */
-
-        if (HAS_PCH_SPLIT(dev)) {
-                I915_WRITE(PCH_PP_CONTROL,
-                           I915_READ(PCH_PP_CONTROL) | PANEL_UNLOCK_REGS);
-        } else if (intel_lvds->pfit_dirty) {
-                I915_WRITE(PP_CONTROL,
-                           (I915_READ(PP_CONTROL) | PANEL_UNLOCK_REGS)
-                           & ~POWER_TARGET_ON);
-        } else {
-                I915_WRITE(PP_CONTROL,
-                           I915_READ(PP_CONTROL) | PANEL_UNLOCK_REGS);
-        }
+        if (!HAS_PCH_SPLIT(encoder->dev) && intel_lvds->pfit_dirty)
+                intel_lvds_disable(intel_lvds);
 }
 
 static void intel_lvds_commit(struct drm_encoder *encoder)
 {
-        struct drm_device *dev = encoder->dev;
-        struct drm_i915_private *dev_priv = dev->dev_private;
         struct intel_lvds *intel_lvds = to_intel_lvds(encoder);
 
-        /* Undo any unlocking done in prepare to prevent accidental
-         * adjustment of the registers.
-         */
-        if (HAS_PCH_SPLIT(dev)) {
-                u32 val = I915_READ(PCH_PP_CONTROL);
-                if ((val & PANEL_UNLOCK_REGS) == PANEL_UNLOCK_REGS)
-                        I915_WRITE(PCH_PP_CONTROL, val & 0x3);
-        } else {
-                u32 val = I915_READ(PP_CONTROL);
-                if ((val & PANEL_UNLOCK_REGS) == PANEL_UNLOCK_REGS)
-                        I915_WRITE(PP_CONTROL, val & 0x3);
-        }
-
         /* Always do a full power on as we do not know what state
          * we were left in.
          */
@@ -1042,6 +1010,19 @@ out:
                 pwm = I915_READ(BLC_PWM_PCH_CTL1);
                 pwm |= PWM_PCH_ENABLE;
                 I915_WRITE(BLC_PWM_PCH_CTL1, pwm);
+                /*
+                 * Unlock registers and just
+                 * leave them unlocked
+                 */
+                I915_WRITE(PCH_PP_CONTROL,
+                           I915_READ(PCH_PP_CONTROL) | PANEL_UNLOCK_REGS);
+        } else {
+                /*
+                 * Unlock registers and just
+                 * leave them unlocked
+                 */
+                I915_WRITE(PP_CONTROL,
+                           I915_READ(PP_CONTROL) | PANEL_UNLOCK_REGS);
         }
         dev_priv->lid_notifier.notifier_call = intel_lid_notify;
         if (acpi_lid_notifier_register(&dev_priv->lid_notifier)) {