[Intel-gfx] [PATCH 1/2] drm/i915/vlv: save/restore the power context base reg

[Jesse Barnes]

Some BIOSes (e.g. the one on the Minnowboard) don't save/restore this
reg.  If it's unlocked, we can just restore the previous value, and if
it's locked (in case the BIOS re-programmed it for us) the write will be
ignored and we'll still have "did it move" sanity check in the PM code to
warn us if something is still amiss.

References: https://bugs.freedesktop.org/show_bug.cgi?id=89611
Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
---
 drivers/gpu/drm/i915/i915_drv.c | 2 ++
 drivers/gpu/drm/i915/i915_drv.h | 1 +
 2 files changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index c1a3cdb5..4d6d6f0 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1104,6 +1104,7 @@ static void vlv_save_gunit_s0ix_state(struct drm_i915_private *dev_priv)
 	/* Gunit-Display CZ domain, 0x182028-0x1821CF */
 	s->gu_ctl0		= I915_READ(VLV_GU_CTL0);
 	s->gu_ctl1		= I915_READ(VLV_GU_CTL1);
+	s->pcbr			= I915_READ(VLV_PCBR);
 	s->clock_gate_dis2	= I915_READ(VLV_GUNIT_CLOCK_GATE2);
 
 	/*
@@ -1198,6 +1199,7 @@ static void vlv_restore_gunit_s0ix_state(struct drm_i915_private *dev_priv)
 	/* Gunit-Display CZ domain, 0x182028-0x1821CF */
 	I915_WRITE(VLV_GU_CTL0,			s->gu_ctl0);
 	I915_WRITE(VLV_GU_CTL1,			s->gu_ctl1);
+	I915_WRITE(VLV_PCBR,			s->pcbr);
 	I915_WRITE(VLV_GUNIT_CLOCK_GATE2,	s->clock_gate_dis2);
 }
 
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b13c552..f3ac683 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -994,6 +994,7 @@ struct vlv_s0ix_state {
 	/* Display 2 CZ domain */
 	u32 gu_ctl0;
 	u32 gu_ctl1;
+	u32 pcbr;
 	u32 clock_gate_dis2;
 };
 
-- 
1.9.1