[Intel-gfx] [PATCH] drm/i915/bxt: Don't save/restore eDP panel power during suspend (v3)

[Matt Roper]

Our attempts save/restore panel power state in i915_suspend.c are
causing unclaimed register warnings on BXT since the registers for this
platform differ from older platforms.

The big hammer suspend/resume shouldn't be necessary for PP since the
connector/encoder hooks should already handle this.  In theory we could
remove this for all platforms, but in practice it's likely that would
cause some regressions since older platforms with LVDS may have
incomplete PP handling.  For now we'll leave the PCH save/restore alone
and change the non-PCH branch to only operate on gen <= 4 so that BXT
and future platforms aren't included.

v2: Typo fix: s/||/&&/

v3: Change non-PCH condition to a gen <= 4 test rather than listing
    VLV/CHV/BXT as specific platforms to exclude; should be more
    future-proof as we add new platforms.  (Daniel)

Cc: Vandana Kannan <vandana.kannan at intel.com>
Cc: Jani Nikula <jani.nikula at linux.intel.com>
Cc: Daniel Vetter <daniel at ffwll.ch>
Cc: drm-intel-fixes at lists.freedesktop.org
Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
---
Although it's the direction we want to move, I'm not brave enough to blow away
the entire PP save/restore for all platforms since I don't have the HW
necessary to deal with the regressions that might pop up.  The consensus on IRC
is that there probably will be a few regressions when we do that, so I'd rather
have people with appropriate platform access make those changes.

 drivers/gpu/drm/i915/i915_suspend.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c
index a2aa09c..a8af594 100644
--- a/drivers/gpu/drm/i915/i915_suspend.c
+++ b/drivers/gpu/drm/i915/i915_suspend.c
@@ -49,7 +49,7 @@ static void i915_save_display(struct drm_device *dev)
 		dev_priv->regfile.savePP_ON_DELAYS = I915_READ(PCH_PP_ON_DELAYS);
 		dev_priv->regfile.savePP_OFF_DELAYS = I915_READ(PCH_PP_OFF_DELAYS);
 		dev_priv->regfile.savePP_DIVISOR = I915_READ(PCH_PP_DIVISOR);
-	} else if (!IS_VALLEYVIEW(dev) && !IS_CHERRYVIEW(dev)) {
+	} else if (INTEL_INFO(dev)->gen <= 4) {
 		dev_priv->regfile.savePP_CONTROL = I915_READ(PP_CONTROL);
 		dev_priv->regfile.savePP_ON_DELAYS = I915_READ(PP_ON_DELAYS);
 		dev_priv->regfile.savePP_OFF_DELAYS = I915_READ(PP_OFF_DELAYS);
@@ -84,7 +84,7 @@ static void i915_restore_display(struct drm_device *dev)
 		I915_WRITE(PCH_PP_OFF_DELAYS, dev_priv->regfile.savePP_OFF_DELAYS);
 		I915_WRITE(PCH_PP_DIVISOR, dev_priv->regfile.savePP_DIVISOR);
 		I915_WRITE(PCH_PP_CONTROL, dev_priv->regfile.savePP_CONTROL);
-	} else if (!IS_VALLEYVIEW(dev) && !IS_CHERRYVIEW(dev)) {
+	} else if (INTEL_INFO(dev)->gen <= 4) {
 		I915_WRITE(PP_ON_DELAYS, dev_priv->regfile.savePP_ON_DELAYS);
 		I915_WRITE(PP_OFF_DELAYS, dev_priv->regfile.savePP_OFF_DELAYS);
 		I915_WRITE(PP_DIVISOR, dev_priv->regfile.savePP_DIVISOR);
-- 
2.1.4