drm/i915/vlv: save/restore the power context base reg

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@virtuousgeek.org>
Tested-by: Darren Hart <dvhart@linux.intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Deepak S <deepak.s@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index cc6ea53d2b81951553d4b135a1760cb127e574c2..a8e6b7cbdf30bc0a390fd39ea066d1baa076ce66 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1095,6 +1095,7 @@ 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);
 
        /*
@@ -1189,6 +1190,7 @@ 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 8727086cf48ccce9e6548df8cf4e1d0df59012e7..b4faa2df9d3d8151c4e7aff8853be20937414096 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1094,6 +1094,7 @@ struct vlv_s0ix_state {
        /* Display 2 CZ domain */
        u32 gu_ctl0;
        u32 gu_ctl1;
+       u32 pcbr;
        u32 clock_gate_dis2;
 };