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

commit 9c25210fd30991e68f93e2ec0857de2d967b5766 upstream.

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>
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 90f05d510c1c67c23c37736c1598a75a8cf45d59..2c100f436ba8e7d2e16c1ed2ec7d581a516327c9 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1093,6 +1093,7 @@ 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);
 
        /*
@@ -1187,6 +1188,7 @@ 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 ddd005ce3a94993e9254cb3ac7a379129b529e4a..44a3c385eea28fc02e0ce2e99785c616705dec56 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -985,6 +985,7 @@ struct vlv_s0ix_state {
        /* Display 2 CZ domain */
        u32 gu_ctl0;
        u32 gu_ctl1;
+       u32 pcbr;
        u32 clock_gate_dis2;
 };