[Intel-gfx] [PATCH 05/17] drm/i915: Don't initialize power seqeuencer delays more than once

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Since we read the current power seqeuncer delays from the registers
(as well as looking at the vbt and spec values) we may end up
corrupting delays we already initialized when we switch to another
pipe and the power seqeuncer there has different values currently
in the registers.

So make sure we only initialize the delays once even if
intel_dp_init_panel_power_sequencer() gets called multiple times.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 7a10464..9a1295d 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4756,6 +4756,10 @@ intel_dp_init_panel_power_sequencer(struct drm_device *dev,
 
 	lockdep_assert_held(&dev_priv->pps_mutex);
 
+	/* already initialized? */
+	if (final->t11_t12 != 0)
+		return;
+
 	if (HAS_PCH_SPLIT(dev)) {
 		pp_ctrl_reg = PCH_PP_CONTROL;
 		pp_on_reg = PCH_PP_ON_DELAYS;
-- 
2.0.4