drm/i915: Wait for LVDS panel power sequence

During mode setting, check to make sure the panel power sequencing has
completed before doing further operations on the device. This
uncovered errors with DPMS not turning the device off as it was left locked.

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

diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index 2e8ddfcba40c8c7d751776fb4d0b6818189b9c7e..63188285d7f9b9904e23ee7aa5dc8a3984a9b451 100644 (file)
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -72,14 +72,16 @@ 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;
-       u32 ctl_reg, lvds_reg;
+       u32 ctl_reg, lvds_reg, stat_reg;
 
        if (HAS_PCH_SPLIT(dev)) {
                ctl_reg = PCH_PP_CONTROL;
                lvds_reg = PCH_LVDS;
+               stat_reg = PCH_PP_STATUS;
        } else {
                ctl_reg = PP_CONTROL;
                lvds_reg = LVDS;
+               stat_reg = PP_STATUS;
        }
 
        I915_WRITE(lvds_reg, I915_READ(lvds_reg) | LVDS_PORT_EN);
@@ -94,17 +96,16 @@ static void intel_lvds_enable(struct intel_lvds *intel_lvds)
                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(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);
+       if (wait_for((I915_READ(stat_reg) & PP_ON) != 0, 1000))
+               DRM_ERROR("timed out waiting for panel to power on\n");
 
        intel_panel_enable_backlight(dev);
 }
@@ -113,24 +114,25 @@ 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;
+       u32 ctl_reg, lvds_reg, stat_reg;
 
        if (HAS_PCH_SPLIT(dev)) {
                ctl_reg = PCH_PP_CONTROL;
                lvds_reg = PCH_LVDS;
+               stat_reg = PCH_PP_STATUS;
        } else {
                ctl_reg = PP_CONTROL;
                lvds_reg = LVDS;
+               stat_reg = PP_STATUS;
        }
 
        intel_panel_disable_backlight(dev);
 
        I915_WRITE(ctl_reg, I915_READ(ctl_reg) & ~POWER_TARGET_ON);
+       if (wait_for((I915_READ(stat_reg) & PP_ON) == 0, 1000))
+               DRM_ERROR("timed out waiting for panel to power off\n");
 
        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;
        }