drm/i915/bxt: Sanitize DC state tracking during system resume
After suspend-to-ram or -disk we don't know what power state the display
HW will be, DC0 or DC9 are both possible states, so reset the software
DC state tracking in these cases. This gets rid of 'DC state mismatch'
error messages during resuming from ram or disk where we expected to be
in DC9 (as set by the suspend handler) but we are in DC0.
v2:
- Remove extra WS in gen9_sanitize_dc_state() (Bob)
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Bob Paauwe <bob.j.paauwe@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461173277-16090-4-git-send-email-imre.deak@intel.com
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index 9000383..8fff080 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -492,10 +492,9 @@
state, rewrites);
}
-static void gen9_set_dc_state(struct drm_i915_private *dev_priv, uint32_t state)
+static u32 gen9_dc_mask(struct drm_i915_private *dev_priv)
{
- uint32_t val;
- uint32_t mask;
+ u32 mask;
mask = DC_STATE_EN_UPTO_DC5;
if (IS_BROXTON(dev_priv))
@@ -503,10 +502,30 @@
else
mask |= DC_STATE_EN_UPTO_DC6;
+ return mask;
+}
+
+void gen9_sanitize_dc_state(struct drm_i915_private *dev_priv)
+{
+ u32 val;
+
+ val = I915_READ(DC_STATE_EN) & gen9_dc_mask(dev_priv);
+
+ DRM_DEBUG_KMS("Resetting DC state tracking from %02x to %02x\n",
+ dev_priv->csr.dc_state, val);
+ dev_priv->csr.dc_state = val;
+}
+
+static void gen9_set_dc_state(struct drm_i915_private *dev_priv, uint32_t state)
+{
+ uint32_t val;
+ uint32_t mask;
+
if (WARN_ON_ONCE(state & ~dev_priv->csr.allowed_dc_mask))
state &= dev_priv->csr.allowed_dc_mask;
val = I915_READ(DC_STATE_EN);
+ mask = gen9_dc_mask(dev_priv);
DRM_DEBUG_KMS("Setting DC state from %02x to %02x\n",
val & mask, state);