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: Luis Henriques <luis.henriques@canonical.com>

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index e35e32f33e31c56e70a559455ffb4026055c1ed1..a458e8393378772c754091737e491330854dc3ba 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1071,6 +1071,7 @@ 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);
 
        /*
@@ -1165,6 +1166,7 @@ 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 09501070d7cda5acfa93340caa9e6eae20d06675..28c7afdfffbcbcd694d1affb72345666a350201e 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -878,6 +878,7 @@ struct vlv_s0ix_state {
        /* Display 2 CZ domain */
        u32 gu_ctl0;
        u32 gu_ctl1;
+       u32 pcbr;
        u32 clock_gate_dis2;
 };