[Intel-gfx] [PATCH] drm/i915/bxt: Fix eDP panel power save/restore

[Matt Roper]

Broxton-specific panel power sequencing was added in commit

        commit b0a08bec96318be54db97c3f0b9e37b52561f9ea
        Author: Vandana Kannan <vandana.kannan at intel.com>
        Date:   Thu Jun 18 11:00:55 2015 +0530

            drm/i915/bxt: eDP Panel Power sequencing

As noted in that commit, Broxton has two sets of registers (and we're
supposed to read which to use from the VBT, although we're punting on
that part at the moment) and also doesn't have a divisor register.
Although we take the BXT-specific details into account at initial system
init, we fail to save/restore the appropriate registers around system
suspend/resume, which leads to unclaimed register warnings at the
moment, and may also fail to save the proper registers once we start
actually paying attention to the VBT.

Cc: Vandana Kannan <vandana.kannan at intel.com>
Cc: drm-intel-fixes at lists.freedesktop.org
Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
---
 drivers/gpu/drm/i915/i915_suspend.c | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c
index bf582fe..61bec8e 100644
--- a/drivers/gpu/drm/i915/i915_suspend.c
+++ b/drivers/gpu/drm/i915/i915_suspend.c
@@ -44,7 +44,18 @@ static void i915_save_display(struct drm_device *dev)
 		dev_priv->regfile.saveLVDS = I915_READ(LVDS);
 
 	/* Panel power sequencer */
-	if (HAS_PCH_SPLIT(dev)) {
+	if (IS_BROXTON(dev)) {
+		/*
+		 * TODO: BXT has 2 sets of PPS registers.
+		 * Correct Register for Broxton need to be identified
+		 * using VBT. hardcoding for now.
+		 *
+		 * There's also no divisor register on Broxton.
+		 */
+		dev_priv->regfile.savePP_CONTROL = I915_READ(BXT_PP_CONTROL(0));
+		dev_priv->regfile.savePP_ON_DELAYS = I915_READ(BXT_PP_ON_DELAYS(0));
+		dev_priv->regfile.savePP_OFF_DELAYS = I915_READ(BXT_PP_OFF_DELAYS(0));
+	} else if (HAS_PCH_SPLIT(dev)) {
 		dev_priv->regfile.savePP_CONTROL = I915_READ(PCH_PP_CONTROL);
 		dev_priv->regfile.savePP_ON_DELAYS = I915_READ(PCH_PP_ON_DELAYS);
 		dev_priv->regfile.savePP_OFF_DELAYS = I915_READ(PCH_PP_OFF_DELAYS);
@@ -83,7 +94,16 @@ static void i915_restore_display(struct drm_device *dev)
 		I915_WRITE(LVDS, dev_priv->regfile.saveLVDS & mask);
 
 	/* Panel power sequencer */
-	if (HAS_PCH_SPLIT(dev)) {
+	if (IS_BROXTON(dev)) {
+		/*
+		 * TODO: BXT has 2 sets of PPS registers.
+		 * Correct Register for Broxton need to be identified
+		 * using VBT. hardcoding for now
+		 */
+		I915_WRITE(BXT_PP_ON_DELAYS(0), dev_priv->regfile.savePP_ON_DELAYS);
+		I915_WRITE(BXT_PP_OFF_DELAYS(0), dev_priv->regfile.savePP_OFF_DELAYS);
+		I915_WRITE(BXT_PP_CONTROL(0), dev_priv->regfile.savePP_CONTROL);
+	} else if (HAS_PCH_SPLIT(dev)) {
 		I915_WRITE(PCH_PP_ON_DELAYS, dev_priv->regfile.savePP_ON_DELAYS);
 		I915_WRITE(PCH_PP_OFF_DELAYS, dev_priv->regfile.savePP_OFF_DELAYS);
 		I915_WRITE(PCH_PP_DIVISOR, dev_priv->regfile.savePP_DIVISOR);
-- 
2.1.4