drm/i915/lvds: Always restore panel-fitter when enabling the LVDS
authorChris Wilson <chris@chris-wilson.co.uk>
Sun, 5 Dec 2010 19:21:18 +0000 (19:21 +0000)
committerChris Wilson <chris@chris-wilson.co.uk>
Sun, 5 Dec 2010 23:01:06 +0000 (23:01 +0000)
Linus Torvalds pointed out that our code was unbalanced when powering on
the panel with respect to the power off sequence in that we were failing
to restore the panel-fitter. The consequence of this would be that
across a simple DPMS off/on for a non-native mode, without an intervening
modeset, the panel fitter would remain disabled and the output would shift
on the panel.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
drivers/gpu/drm/i915/intel_lvds.c

index f79327fc66539937d686ba604823f81895f2fa83..25bcedf386fd5e07f93b2c2f77d78dd8dc905170 100644 (file)
@@ -68,7 +68,7 @@ static struct intel_lvds *intel_attached_lvds(struct drm_connector *connector)
 /**
  * Sets the power state for the panel.
  */
-static void intel_lvds_set_power(struct intel_lvds *intel_lvds, bool on)
+static void intel_lvds_enable(struct intel_lvds *intel_lvds)
 {
        struct drm_device *dev = intel_lvds->base.base.dev;
        struct drm_i915_private *dev_priv = dev->dev_private;
@@ -82,26 +82,61 @@ static void intel_lvds_set_power(struct intel_lvds *intel_lvds, bool on)
                lvds_reg = LVDS;
        }
 
-       if (on) {
-               I915_WRITE(lvds_reg, I915_READ(lvds_reg) | LVDS_PORT_EN);
-               I915_WRITE(ctl_reg, I915_READ(ctl_reg) | POWER_TARGET_ON);
-               intel_panel_set_backlight(dev, dev_priv->backlight_level);
-       } else {
-               dev_priv->backlight_level = intel_panel_get_backlight(dev);
-
-               intel_panel_set_backlight(dev, 0);
-               I915_WRITE(ctl_reg, I915_READ(ctl_reg) & ~POWER_TARGET_ON);
+       I915_WRITE(lvds_reg, I915_READ(lvds_reg) | LVDS_PORT_EN);
 
-               if (intel_lvds->pfit_control) {
-                       if (wait_for((I915_READ(PP_STATUS) & PP_ON) == 0, 1000))
-                               DRM_ERROR("timed out waiting for panel to power off\n");
-                       I915_WRITE(PFIT_CONTROL, 0);
-                       intel_lvds->pfit_control = 0;
+       if (intel_lvds->pfit_dirty) {
+               /*
+                * Enable automatic panel scaling so that non-native modes
+                * fill the screen.  The panel fitter should only be
+                * adjusted whilst the pipe is disabled, according to
+                * register description and PRM.
+                */
+               DRM_DEBUG_KMS("applying panel-fitter: %x, %x\n",
+                             intel_lvds->pfit_control,
+                             intel_lvds->pfit_pgm_ratios);
+               if (wait_for((I915_READ(PP_STATUS) & PP_ON) == 0, 1000)) {
+                       DRM_ERROR("timed out waiting for panel to power off\n");
+               } else {
+                       I915_WRITE(PFIT_PGM_RATIOS, intel_lvds->pfit_pgm_ratios);
+                       I915_WRITE(PFIT_CONTROL, intel_lvds->pfit_control);
                        intel_lvds->pfit_dirty = false;
                }
+       }
+
+       I915_WRITE(ctl_reg, I915_READ(ctl_reg) | POWER_TARGET_ON);
+       POSTING_READ(lvds_reg);
+
+       intel_panel_set_backlight(dev, dev_priv->backlight_level);
+}
 
-               I915_WRITE(lvds_reg, I915_READ(lvds_reg) & ~LVDS_PORT_EN);
+static void intel_lvds_disable(struct intel_lvds *intel_lvds)
+{
+       struct drm_device *dev = intel_lvds->base.base.dev;
+       struct drm_i915_private *dev_priv = dev->dev_private;
+       u32 ctl_reg, lvds_reg;
+
+       if (HAS_PCH_SPLIT(dev)) {
+               ctl_reg = PCH_PP_CONTROL;
+               lvds_reg = PCH_LVDS;
+       } else {
+               ctl_reg = PP_CONTROL;
+               lvds_reg = LVDS;
+       }
+
+       dev_priv->backlight_level = intel_panel_get_backlight(dev);
+       intel_panel_set_backlight(dev, 0);
+
+       I915_WRITE(ctl_reg, I915_READ(ctl_reg) & ~POWER_TARGET_ON);
+
+       if (intel_lvds->pfit_control) {
+               if (wait_for((I915_READ(PP_STATUS) & PP_ON) == 0, 1000))
+                       DRM_ERROR("timed out waiting for panel to power off\n");
+
+               I915_WRITE(PFIT_CONTROL, 0);
+               intel_lvds->pfit_dirty = true;
        }
+
+       I915_WRITE(lvds_reg, I915_READ(lvds_reg) & ~LVDS_PORT_EN);
        POSTING_READ(lvds_reg);
 }
 
@@ -110,9 +145,9 @@ static void intel_lvds_dpms(struct drm_encoder *encoder, int mode)
        struct intel_lvds *intel_lvds = to_intel_lvds(encoder);
 
        if (mode == DRM_MODE_DPMS_ON)
-               intel_lvds_set_power(intel_lvds, true);
+               intel_lvds_enable(intel_lvds);
        else
-               intel_lvds_set_power(intel_lvds, false);
+               intel_lvds_disable(intel_lvds);
 
        /* XXX: We never power down the LVDS pairs. */
 }
@@ -411,43 +446,18 @@ static void intel_lvds_commit(struct drm_encoder *encoder)
        /* Always do a full power on as we do not know what state
         * we were left in.
         */
-       intel_lvds_set_power(intel_lvds, true);
+       intel_lvds_enable(intel_lvds);
 }
 
 static void intel_lvds_mode_set(struct drm_encoder *encoder,
                                struct drm_display_mode *mode,
                                struct drm_display_mode *adjusted_mode)
 {
-       struct drm_device *dev = encoder->dev;
-       struct drm_i915_private *dev_priv = dev->dev_private;
-       struct intel_lvds *intel_lvds = to_intel_lvds(encoder);
-
        /*
         * The LVDS pin pair will already have been turned on in the
         * intel_crtc_mode_set since it has a large impact on the DPLL
         * settings.
         */
-
-       if (HAS_PCH_SPLIT(dev))
-               return;
-
-       if (!intel_lvds->pfit_dirty)
-               return;
-
-       /*
-        * Enable automatic panel scaling so that non-native modes fill the
-        * screen.  Should be enabled before the pipe is enabled, according to
-        * register description and PRM.
-        */
-       DRM_DEBUG_KMS("applying panel-fitter: %x, %x\n",
-                     intel_lvds->pfit_control,
-                     intel_lvds->pfit_pgm_ratios);
-       if (wait_for((I915_READ(PP_STATUS) & PP_ON) == 0, 1000))
-               DRM_ERROR("timed out waiting for panel to power off\n");
-
-       I915_WRITE(PFIT_PGM_RATIOS, intel_lvds->pfit_pgm_ratios);
-       I915_WRITE(PFIT_CONTROL, intel_lvds->pfit_control);
-       intel_lvds->pfit_dirty = false;
 }
 
 /**