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

[ Upstream commit 9c25210fd30991e68f93e2ec0857de2d967b5766 ]

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>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 1787b1846f18cd1f851901975de7c544eac2242e..4d4838d9b8b7d832a08d7c8c1e2afc48cb1e936c 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1141,6 +1141,7 @@ 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);
 
        /*
@@ -1235,6 +1236,7 @@ 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 45434333b2891329f933c487ecb5f65986bf7d5b..a84971351eeeb5d528f814b571f37fed1bfdb26b 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -938,6 +938,7 @@ struct vlv_s0ix_state {
        /* Display 2 CZ domain */
        u32 gu_ctl0;
        u32 gu_ctl1;
+       u32 pcbr;
        u32 clock_gate_dis2;
 };