Merge tag 'drm-intel-fixes-2016-02-22' of git://anongit.freedesktop.org/drm-intel into drm-fixes

This is a bit large, but it really helps Skylake bugs we are seeing
on a number of laptops.

Most of the commits are quite similar, ensuring the display power
doesn't vanish under us during hardware access. Also do note that it's
not just Skylake that's affected.

* tag 'drm-intel-fixes-2016-02-22' of git://anongit.freedesktop.org/drm-intel:
  drm/i915/gen9: Verify and enforce dc6 state writes
  drm/i915/gen9: Check for DC state mismatch
  drm/i915/skl: Ensure HW is powered during DDB HW state readout
  drm/i915/lvds: Ensure the HW is powered during HW state readout
  drm/i915/hdmi: Ensure the HW is powered during HW state readout
  drm/i915/dsi: Ensure the HW is powered during HW state readout
  drm/i915/dp: Ensure the HW is powered during HW state readout
  drm/i915: Ensure the HW is powered when accessing the CRC HW block
  drm/i915/ddi: Ensure the HW is powered during HW state readout
  drm/i915/crt: Ensure the HW is powered during HW state readout
  drm/i915: Ensure the HW is powered during HW access in assert_pipe
  drm/i915: Ensure the HW is powered when disabling VGA
  drm/i915/ibx: Ensure the HW is powered during PLL HW readout
  drm/i915: Ensure the HW is powered during display pipe HW readout
  drm/i915: Add helper to get a display power ref if it was already enabled

13 files changed, 367 insertions, 93 deletions

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 0fc38bb7276c..cf39ed3133d6 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -825,8 +825,11 @@ static int i915_interrupt_info(struct seq_file *m, void *data)
 		}
 
 		for_each_pipe(dev_priv, pipe) {
-			if (!intel_display_power_is_enabled(dev_priv,
-						POWER_DOMAIN_PIPE(pipe))) {
+			enum intel_display_power_domain power_domain;
+
+			power_domain = POWER_DOMAIN_PIPE(pipe);
+			if (!intel_display_power_get_if_enabled(dev_priv,
+								power_domain)) {
 				seq_printf(m, "Pipe %c power disabled\n",
 					   pipe_name(pipe));
 				continue;
@@ -840,6 +843,8 @@ static int i915_interrupt_info(struct seq_file *m, void *data)
 			seq_printf(m, "Pipe %c IER:\t%08x\n",
 				   pipe_name(pipe),
 				   I915_READ(GEN8_DE_PIPE_IER(pipe)));
+
+			intel_display_power_put(dev_priv, power_domain);
 		}
 
 		seq_printf(m, "Display Engine port interrupt mask:\t%08x\n",
@@ -3985,6 +3990,7 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,
 	struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe];
 	struct intel_crtc *crtc = to_intel_crtc(intel_get_crtc_for_pipe(dev,
 									pipe));
+	enum intel_display_power_domain power_domain;
 	u32 val = 0; /* shut up gcc */
 	int ret;
 
@@ -3995,7 +4001,8 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,
 	if (pipe_crc->source && source)
 		return -EINVAL;
 
-	if (!intel_display_power_is_enabled(dev_priv, POWER_DOMAIN_PIPE(pipe))) {
+	power_domain = POWER_DOMAIN_PIPE(pipe);
+	if (!intel_display_power_get_if_enabled(dev_priv, power_domain)) {
 		DRM_DEBUG_KMS("Trying to capture CRC while pipe is off\n");
 		return -EIO;
 	}
@@ -4012,7 +4019,7 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,
 		ret = ivb_pipe_crc_ctl_reg(dev, pipe, &source, &val);
 
 	if (ret != 0)
-		return ret;
+		goto out;
 
 	/* none -> real source transition */
 	if (source) {
@@ -4024,8 +4031,10 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,
 		entries = kcalloc(INTEL_PIPE_CRC_ENTRIES_NR,
 				  sizeof(pipe_crc->entries[0]),
 				  GFP_KERNEL);
-		if (!entries)
-			return -ENOMEM;
+		if (!entries) {
+			ret = -ENOMEM;
+			goto out;
+		}
 
 		/*
 		 * When IPS gets enabled, the pipe CRC changes. Since IPS gets
@@ -4081,7 +4090,12 @@ static int pipe_crc_set_source(struct drm_device *dev, enum pipe pipe,
 		hsw_enable_ips(crtc);
 	}
 
-	return 0;
+	ret = 0;
+
+out:
+	intel_display_power_put(dev_priv, power_domain);
+
+	return ret;
 }
 
 /*
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e7cd311e9fbb..b0847b915545 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -751,6 +751,7 @@ struct intel_csr {
 	uint32_t mmio_count;
 	i915_reg_t mmioaddr[8];
 	uint32_t mmiodata[8];
+	uint32_t dc_state;
 };
 
 #define DEV_INFO_FOR_EACH_FLAG(func, sep) \
diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index 9c89df1af036..a7b4a524fadd 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -71,22 +71,29 @@ static bool intel_crt_get_hw_state(struct intel_encoder *encoder,
 	struct intel_crt *crt = intel_encoder_to_crt(encoder);
 	enum intel_display_power_domain power_domain;
 	u32 tmp;
+	bool ret;
 
 	power_domain = intel_display_port_power_domain(encoder);
-	if (!intel_display_power_is_enabled(dev_priv, power_domain))
+	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
 		return false;
 
+	ret = false;
+
 	tmp = I915_READ(crt->adpa_reg);
 
 	if (!(tmp & ADPA_DAC_ENABLE))
-		return false;
+		goto out;
 
 	if (HAS_PCH_CPT(dev))
 		*pipe = PORT_TO_PIPE_CPT(tmp);
 	else
 		*pipe = PORT_TO_PIPE(tmp);
 
-	return true;
+	ret = true;
+out:
+	intel_display_power_put(dev_priv, power_domain);
+
+	return ret;
 }
 
 static unsigned int intel_crt_get_flags(struct intel_encoder *encoder)
diff --git a/drivers/gpu/drm/i915/intel_csr.c b/drivers/gpu/drm/i915/intel_csr.c
index 9bb63a85997a..647d85e77c2f 100644
--- a/drivers/gpu/drm/i915/intel_csr.c
+++ b/drivers/gpu/drm/i915/intel_csr.c
@@ -240,6 +240,8 @@ void intel_csr_load_program(struct drm_i915_private *dev_priv)
 		I915_WRITE(dev_priv->csr.mmioaddr[i],
 			   dev_priv->csr.mmiodata[i]);
 	}
+
+	dev_priv->csr.dc_state = 0;
 }
 
 static uint32_t *parse_csr_fw(struct drm_i915_private *dev_priv,
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 54a165b9c92d..0f3df2c39f7c 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1969,13 +1969,16 @@ bool intel_ddi_connector_get_hw_state(struct intel_connector *intel_connector)
 	enum transcoder cpu_transcoder;
 	enum intel_display_power_domain power_domain;
 	uint32_t tmp;
+	bool ret;
 
 	power_domain = intel_display_port_power_domain(intel_encoder);
-	if (!intel_display_power_is_enabled(dev_priv, power_domain))
+	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
 		return false;
 
-	if (!intel_encoder->get_hw_state(intel_encoder, &pipe))
-		return false;
+	if (!intel_encoder->get_hw_state(intel_encoder, &pipe)) {
+		ret = false;
+		goto out;
+	}
 
 	if (port == PORT_A)
 		cpu_transcoder = TRANSCODER_EDP;
@@ -1987,23 +1990,33 @@ bool intel_ddi_connector_get_hw_state(struct intel_connector *intel_connector)
 	switch (tmp & TRANS_DDI_MODE_SELECT_MASK) {
 	case TRANS_DDI_MODE_SELECT_HDMI:
 	case TRANS_DDI_MODE_SELECT_DVI:
-		return (type == DRM_MODE_CONNECTOR_HDMIA);
+		ret = type == DRM_MODE_CONNECTOR_HDMIA;
+		break;
 
 	case TRANS_DDI_MODE_SELECT_DP_SST:
-		if (type == DRM_MODE_CONNECTOR_eDP)
-			return true;
-		return (type == DRM_MODE_CONNECTOR_DisplayPort);
+		ret = type == DRM_MODE_CONNECTOR_eDP ||
+		      type == DRM_MODE_CONNECTOR_DisplayPort;
+		break;
+
 	case TRANS_DDI_MODE_SELECT_DP_MST:
 		/* if the transcoder is in MST state then
 		 * connector isn't connected */
-		return false;
+		ret = false;
+		break;
 
 	case TRANS_DDI_MODE_SELECT_FDI:
-		return (type == DRM_MODE_CONNECTOR_VGA);
+		ret = type == DRM_MODE_CONNECTOR_VGA;
+		break;
 
 	default:
-		return false;
+		ret = false;
+		break;
 	}
+
+out:
+	intel_display_power_put(dev_priv, power_domain);
+
+	return ret;
 }
 
 bool intel_ddi_get_hw_state(struct intel_encoder *encoder,
@@ -2015,15 +2028,18 @@ bool intel_ddi_get_hw_state(struct intel_encoder *encoder,
 	enum intel_display_power_domain power_domain;
 	u32 tmp;
 	int i;
+	bool ret;
 
 	power_domain = intel_display_port_power_domain(encoder);
-	if (!intel_display_power_is_enabled(dev_priv, power_domain))
+	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
 		return false;
 
+	ret = false;
+
 	tmp = I915_READ(DDI_BUF_CTL(port));
 
 	if (!(tmp & DDI_BUF_CTL_ENABLE))
-		return false;
+		goto out;
 
 	if (port == PORT_A) {
 		tmp = I915_READ(TRANS_DDI_FUNC_CTL(TRANSCODER_EDP));
@@ -2041,25 +2057,32 @@ bool intel_ddi_get_hw_state(struct intel_encoder *encoder,
 			break;
 		}
 
-		return true;
-	} else {
-		for (i = TRANSCODER_A; i <= TRANSCODER_C; i++) {
-			tmp = I915_READ(TRANS_DDI_FUNC_CTL(i));
+		ret = true;
 
-			if ((tmp & TRANS_DDI_PORT_MASK)
-			    == TRANS_DDI_SELECT_PORT(port)) {
-				if ((tmp & TRANS_DDI_MODE_SELECT_MASK) == TRANS_DDI_MODE_SELECT_DP_MST)
-					return false;
+		goto out;
+	}
 
-				*pipe = i;
-				return true;
-			}
+	for (i = TRANSCODER_A; i <= TRANSCODER_C; i++) {
+		tmp = I915_READ(TRANS_DDI_FUNC_CTL(i));
+
+		if ((tmp & TRANS_DDI_PORT_MASK) == TRANS_DDI_SELECT_PORT(port)) {
+			if ((tmp & TRANS_DDI_MODE_SELECT_MASK) ==
+			    TRANS_DDI_MODE_SELECT_DP_MST)
+				goto out;
+
+			*pipe = i;
+			ret = true;
+
+			goto out;
 		}
 	}
 
 	DRM_DEBUG_KMS("No pipe for ddi port %c found\n", port_name(port));
 
-	return false;
+out:
+	intel_display_power_put(dev_priv, power_domain);
+
+	return ret;
 }
 
 void intel_ddi_enable_pipe_clock(struct intel_crtc *intel_crtc)
@@ -2508,12 +2531,14 @@ static bool hsw_ddi_wrpll_get_hw_state(struct drm_i915_private *dev_priv,
 {
 	uint32_t val;
 
-	if (!intel_display_power_is_enabled(dev_priv, POWER_DOMAIN_PLLS))
+	if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
 		return false;
 
 	val = I915_READ(WRPLL_CTL(pll->id));
 	hw_state->wrpll = val;
 
+	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
+
 	return val & WRPLL_PLL_ENABLE;
 }
 
@@ -2523,12 +2548,14 @@ static bool hsw_ddi_spll_get_hw_state(struct drm_i915_private *dev_priv,
 {
 	uint32_t val;
 
-	if (!intel_display_power_is_enabled(dev_priv, POWER_DOMAIN_PLLS))
+	if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
 		return false;
 
 	val = I915_READ(SPLL_CTL);
 	hw_state->spll = val;
 
+	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
+
 	return val & SPLL_PLL_ENABLE;
 }
 
@@ -2645,16 +2672,19 @@ static bool skl_ddi_pll_get_hw_state(struct drm_i915_private *dev_priv,
 	uint32_t val;
 	unsigned int dpll;
 	const struct skl_dpll_regs *regs = skl_dpll_regs;
+	bool ret;
 
-	if (!intel_display_power_is_enabled(dev_priv, POWER_DOMAIN_PLLS))
+	if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
 		return false;
 
+	ret = false;
+
 	/* DPLL0 is not part of the shared DPLLs, so pll->id is 0 for DPLL1 */
 	dpll = pll->id + 1;
 
 	val = I915_READ(regs[pll->id].ctl);
 	if (!(val & LCPLL_PLL_ENABLE))
-		return false;
+		goto out;
 
 	val = I915_READ(DPLL_CTRL1);
 	hw_state->ctrl1 = (val >> (dpll * 6)) & 0x3f;
@@ -2664,8 +2694,12 @@ static bool skl_ddi_pll_get_hw_state(struct drm_i915_private *dev_priv,
 		hw_state->cfgcr1 = I915_READ(regs[pll->id].cfgcr1);
 		hw_state->cfgcr2 = I915_READ(regs[pll->id].cfgcr2);
 	}
+	ret = true;
 
-	return true;
+out:
+	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
+
+	return ret;
 }
 
 static void skl_shared_dplls_init(struct drm_i915_private *dev_priv)
@@ -2932,13 +2966,16 @@ static bool bxt_ddi_pll_get_hw_state(struct drm_i915_private *dev_priv,
 {
 	enum port port = (enum port)pll->id;	/* 1:1 port->PLL mapping */
 	uint32_t val;
+	bool ret;
 
-	if (!intel_display_power_is_enabled(dev_priv, POWER_DOMAIN_PLLS))
+	if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
 		return false;
 
+	ret = false;
+
 	val = I915_READ(BXT_PORT_PLL_ENABLE(port));
 	if (!(val & PORT_PLL_ENABLE))
-		return false;
+		goto out;
 
 	hw_state->ebb0 = I915_READ(BXT_PORT_PLL_EBB_0(port));
 	hw_state->ebb0 &= PORT_PLL_P1_MASK | PORT_PLL_P2_MASK;
@@ -2985,7 +3022,12 @@ static bool bxt_ddi_pll_get_hw_state(struct drm_i915_private *dev_priv,
 				 I915_READ(BXT_PORT_PCS_DW12_LN23(port)));
 	hw_state->pcsdw12 &= LANE_STAGGER_MASK | LANESTAGGER_STRAP_OVRD;
 
-	return true;
+	ret = true;
+
+out:
+	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
+
+	return ret;
 }
 
 static void bxt_shared_dplls_init(struct drm_i915_private *dev_priv)
@@ -3120,11 +3162,15 @@ bool intel_ddi_is_audio_enabled(struct drm_i915_private *dev_priv,
 {
 	u32 temp;
 
-	if (intel_display_power_is_enabled(dev_priv, POWER_DOMAIN_AUDIO)) {
+	if (intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_AUDIO)) {
 		temp = I915_READ(HSW_AUD_PIN_ELD_CP_VLD);
+
+		intel_display_power_put(dev_priv, POWER_DOMAIN_AUDIO);
+
 		if (temp & AUDIO_OUTPUT_ENABLE(intel_crtc->pipe))
 			return true;
 	}
+
 	return false;
 }
 
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 5feb65725c04..46947fffd599 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1351,18 +1351,21 @@ void assert_pipe(struct drm_i915_private *dev_priv,
 	bool cur_state;
 	enum transcoder cpu_transcoder = intel_pipe_to_cpu_transcoder(dev_priv,
 								      pipe);
+	enum intel_display_power_domain power_domain;
 
 	/* if we need the pipe quirk it must be always on */
 	if ((pipe == PIPE_A && dev_priv->quirks & QUIRK_PIPEA_FORCE) ||
 	    (pipe == PIPE_B && dev_priv->quirks & QUIRK_PIPEB_FORCE))
 		state = true;
 
-	if (!intel_display_power_is_enabled(dev_priv,
-				POWER_DOMAIN_TRANSCODER(cpu_transcoder))) {
-		cur_state = false;
-	} else {
+	power_domain = POWER_DOMAIN_TRANSCODER(cpu_transcoder);
+	if (intel_display_power_get_if_enabled(dev_priv, power_domain)) {
 		u32 val = I915_READ(PIPECONF(cpu_transcoder));
 		cur_state = !!(val & PIPECONF_ENABLE);
+
+		intel_display_power_put(dev_priv, power_domain);
+	} else {
+		cur_state = false;
 	}
 
 	I915_STATE_WARN(cur_state != state,
@@ -8171,18 +8174,22 @@ static bool i9xx_get_pipe_config(struct intel_crtc *crtc,
 {
 	struct drm_device *dev = crtc->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
+	enum intel_display_power_domain power_domain;
 	uint32_t tmp;
+	bool ret;
 
-	if (!intel_display_power_is_enabled(dev_priv,
-					    POWER_DOMAIN_PIPE(crtc->pipe)))
+	power_domain = POWER_DOMAIN_PIPE(crtc->pipe);
+	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
 		return false;
 
 	pipe_config->cpu_transcoder = (enum transcoder) crtc->pipe;
 	pipe_config->shared_dpll = DPLL_ID_PRIVATE;
 
+	ret = false;
+
 	tmp = I915_READ(PIPECONF(crtc->pipe));
 	if (!(tmp & PIPECONF_ENABLE))
-		return false;
+		goto out;
 
 	if (IS_G4X(dev) || IS_VALLEYVIEW(dev) || IS_CHERRYVIEW(dev)) {
 		switch (tmp & PIPECONF_BPC_MASK) {
@@ -8262,7 +8269,12 @@ static bool i9xx_get_pipe_config(struct intel_crtc *crtc,
 	pipe_config->base.adjusted_mode.crtc_clock =
 		pipe_config->port_clock / pipe_config->pixel_multiplier;
 
-	return true;
+	ret = true;
+
+out:
+	intel_display_power_put(dev_priv, power_domain);
+
+	return ret;
 }
 
 static void ironlake_init_pch_refclk(struct drm_device *dev)
@@ -9366,18 +9378,21 @@ static bool ironlake_get_pipe_config(struct intel_crtc *crtc,
 {
 	struct drm_device *dev = crtc->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
+	enum intel_display_power_domain power_domain;
 	uint32_t tmp;
+	bool ret;
 
-	if (!intel_display_power_is_enabled(dev_priv,
-					    POWER_DOMAIN_PIPE(crtc->pipe)))
+	power_domain = POWER_DOMAIN_PIPE(crtc->pipe);
+	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
 		return false;
 
 	pipe_config->cpu_transcoder = (enum transcoder) crtc->pipe;
 	pipe_config->shared_dpll = DPLL_ID_PRIVATE;
 
+	ret = false;
 	tmp = I915_READ(PIPECONF(crtc->pipe));
 	if (!(tmp & PIPECONF_ENABLE))
-		return false;
+		goto out;
 
 	switch (tmp & PIPECONF_BPC_MASK) {
 	case PIPECONF_6BPC:
@@ -9440,7 +9455,12 @@ static bool ironlake_get_pipe_config(struct intel_crtc *crtc,
 
 	ironlake_get_pfit_config(crtc, pipe_config);
 
-	return true;
+	ret = true;
+
+out:
+	intel_display_power_put(dev_priv, power_domain);
+
+	return ret;
 }
 
 static void assert_can_disable_lcpll(struct drm_i915_private *dev_priv)
@@ -9950,12 +9970,17 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 {
 	struct drm_device *dev = crtc->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	enum intel_display_power_domain pfit_domain;
+	enum intel_display_power_domain power_domain;
+	unsigned long power_domain_mask;
 	uint32_t tmp;
+	bool ret;
 
-	if (!intel_display_power_is_enabled(dev_priv,
-					 POWER_DOMAIN_PIPE(crtc->pipe)))
+	power_domain = POWER_DOMAIN_PIPE(crtc->pipe);
+	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
 		return false;
+	power_domain_mask = BIT(power_domain);
+
+	ret = false;
 
 	pipe_config->cpu_transcoder = (enum transcoder) crtc->pipe;
 	pipe_config->shared_dpll = DPLL_ID_PRIVATE;
@@ -9982,13 +10007,14 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 			pipe_config->cpu_transcoder = TRANSCODER_EDP;
 	}
 
-	if (!intel_display_power_is_enabled(dev_priv,
-			POWER_DOMAIN_TRANSCODER(pipe_config->cpu_transcoder)))
-		return false;
+	power_domain = POWER_DOMAIN_TRANSCODER(pipe_config->cpu_transcoder);
+	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
+		goto out;
+	power_domain_mask |= BIT(power_domain);
 
 	tmp = I915_READ(PIPECONF(pipe_config->cpu_transcoder));
 	if (!(tmp & PIPECONF_ENABLE))
-		return false;
+		goto out;
 
 	haswell_get_ddi_port_state(crtc, pipe_config);
 
@@ -9998,14 +10024,14 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 		skl_init_scalers(dev, crtc, pipe_config);
 	}
 
-	pfit_domain = POWER_DOMAIN_PIPE_PANEL_FITTER(crtc->pipe);
-
 	if (INTEL_INFO(dev)->gen >= 9) {
 		pipe_config->scaler_state.scaler_id = -1;
 		pipe_config->scaler_state.scaler_users &= ~(1 << SKL_CRTC_INDEX);
 	}
 
-	if (intel_display_power_is_enabled(dev_priv, pfit_domain)) {
+	power_domain = POWER_DOMAIN_PIPE_PANEL_FITTER(crtc->pipe);
+	if (intel_display_power_get_if_enabled(dev_priv, power_domain)) {
+		power_domain_mask |= BIT(power_domain);
 		if (INTEL_INFO(dev)->gen >= 9)
 			skylake_get_pfit_config(crtc, pipe_config);
 		else
@@ -10023,7 +10049,13 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 		pipe_config->pixel_multiplier = 1;
 	}
 
-	return true;
+	ret = true;
+
+out:
+	for_each_power_domain(power_domain, power_domain_mask)
+		intel_display_power_put(dev_priv, power_domain);
+
+	return ret;
 }
 
 static void i845_update_cursor(struct drm_crtc *crtc, u32 base, bool on)
@@ -13630,7 +13662,7 @@ static bool ibx_pch_dpll_get_hw_state(struct drm_i915_private *dev_priv,
 {
 	uint32_t val;
 
-	if (!intel_display_power_is_enabled(dev_priv, POWER_DOMAIN_PLLS))
+	if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
 		return false;
 
 	val = I915_READ(PCH_DPLL(pll->id));
@@ -13638,6 +13670,8 @@ static bool ibx_pch_dpll_get_hw_state(struct drm_i915_private *dev_priv,
 	hw_state->fp0 = I915_READ(PCH_FP0(pll->id));
 	hw_state->fp1 = I915_READ(PCH_FP1(pll->id));
 
+	intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
+
 	return val & DPLL_VCO_ENABLE;
 }
 
@@ -15568,10 +15602,12 @@ void i915_redisable_vga(struct drm_device *dev)
 	 * level, just check if the power well is enabled instead of trying to
 	 * follow the "don't touch the power well if we don't need it" policy
 	 * the rest of the driver uses. */
-	if (!intel_display_power_is_enabled(dev_priv, POWER_DOMAIN_VGA))
+	if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_VGA))
 		return;
 
 	i915_redisable_vga_power_on(dev);
+
+	intel_display_power_put(dev_priv, POWER_DOMAIN_VGA);
 }
 
 static bool primary_get_hw_state(struct intel_plane *plane)
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 1bbd67b046da..1d8de43bed56 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -2362,15 +2362,18 @@ static bool intel_dp_get_hw_state(struct intel_encoder *encoder,
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	enum intel_display_power_domain power_domain;
 	u32 tmp;
+	bool ret;
 
 	power_domain = intel_display_port_power_domain(encoder);
-	if (!intel_display_power_is_enabled(dev_priv, power_domain))
+	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
 		return false;
 
+	ret = false;
+
 	tmp = I915_READ(intel_dp->output_reg);
 
 	if (!(tmp & DP_PORT_EN))
-		return false;
+		goto out;
 
 	if (IS_GEN7(dev) && port == PORT_A) {
 		*pipe = PORT_TO_PIPE_CPT(tmp);
@@ -2381,7 +2384,9 @@ static bool intel_dp_get_hw_state(struct intel_encoder *encoder,
 			u32 trans_dp = I915_READ(TRANS_DP_CTL(p));
 			if (TRANS_DP_PIPE_TO_PORT(trans_dp) == port) {
 				*pipe = p;
-				return true;
+				ret = true;
+
+				goto out;
 			}
 		}
 
@@ -2393,7 +2398,12 @@ static bool intel_dp_get_hw_state(struct intel_encoder *encoder,
 		*pipe = PORT_TO_PIPE(tmp);
 	}
 
-	return true;
+	ret = true;
+
+out:
+	intel_display_power_put(dev_priv, power_domain);
+
+	return ret;
 }
 
 static void intel_dp_get_config(struct intel_encoder *encoder,
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index ea5415851c6e..df7f3cb66056 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1428,6 +1428,8 @@ bool __intel_display_power_is_enabled(struct drm_i915_private *dev_priv,
 				      enum intel_display_power_domain domain);
 void intel_display_power_get(struct drm_i915_private *dev_priv,
 			     enum intel_display_power_domain domain);
+bool intel_display_power_get_if_enabled(struct drm_i915_private *dev_priv,
+					enum intel_display_power_domain domain);
 void intel_display_power_put(struct drm_i915_private *dev_priv,
 			     enum intel_display_power_domain domain);
 
@@ -1514,6 +1516,7 @@ enable_rpm_wakeref_asserts(struct drm_i915_private *dev_priv)
 	enable_rpm_wakeref_asserts(dev_priv)
 
 void intel_runtime_pm_get(struct drm_i915_private *dev_priv);
+bool intel_runtime_pm_get_if_in_use(struct drm_i915_private *dev_priv);
 void intel_runtime_pm_get_noresume(struct drm_i915_private *dev_priv);
 void intel_runtime_pm_put(struct drm_i915_private *dev_priv);
 
diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
index 44742fa2f616..0193c62a53ef 100644
--- a/drivers/gpu/drm/i915/intel_dsi.c
+++ b/drivers/gpu/drm/i915/intel_dsi.c
@@ -664,13 +664,16 @@ static bool intel_dsi_get_hw_state(struct intel_encoder *encoder,
 	struct drm_device *dev = encoder->base.dev;
 	enum intel_display_power_domain power_domain;
 	enum port port;
+	bool ret;
 
 	DRM_DEBUG_KMS("\n");
 
 	power_domain = intel_display_port_power_domain(encoder);
-	if (!intel_display_power_is_enabled(dev_priv, power_domain))
+	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
 		return false;
 
+	ret = false;
+
 	/* XXX: this only works for one DSI output */
 	for_each_dsi_port(port, intel_dsi->ports) {
 		i915_reg_t ctrl_reg = IS_BROXTON(dev) ?
@@ -691,12 +694,16 @@ static bool intel_dsi_get_hw_state(struct intel_encoder *encoder,
 		if (dpi_enabled || (func & CMD_MODE_DATA_WIDTH_MASK)) {
 			if (I915_READ(MIPI_DEVICE_READY(port)) & DEVICE_READY) {
 				*pipe = port == PORT_A ? PIPE_A : PIPE_B;
-				return true;
+				ret = true;
+
+				goto out;
 			}
 		}
 	}
+out:
+	intel_display_power_put(dev_priv, power_domain);
 
-	return false;
+	return ret;
 }
 
 static void intel_dsi_get_config(struct intel_encoder *encoder,
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 4a77639a489d..cb5d1b15755c 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -880,15 +880,18 @@ static bool intel_hdmi_get_hw_state(struct intel_encoder *encoder,
 	struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(&encoder->base);
 	enum intel_display_power_domain power_domain;
 	u32 tmp;
+	bool ret;
 
 	power_domain = intel_display_port_power_domain(encoder);
-	if (!intel_display_power_is_enabled(dev_priv, power_domain))
+	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
 		return false;
 
+	ret = false;
+
 	tmp = I915_READ(intel_hdmi->hdmi_reg);
 
 	if (!(tmp & SDVO_ENABLE))
-		return false;
+		goto out;
 
 	if (HAS_PCH_CPT(dev))
 		*pipe = PORT_TO_PIPE_CPT(tmp);
@@ -897,7 +900,12 @@ static bool intel_hdmi_get_hw_state(struct intel_encoder *encoder,
 	else
 		*pipe = PORT_TO_PIPE(tmp);
 
-	return true;
+	ret = true;
+
+out:
+	intel_display_power_put(dev_priv, power_domain);
+
+	return ret;
 }
 
 static void intel_hdmi_get_config(struct intel_encoder *encoder,
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index 0da0240caf81..bc04d8d29acb 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -75,22 +75,30 @@ static bool intel_lvds_get_hw_state(struct intel_encoder *encoder,
 	struct intel_lvds_encoder *lvds_encoder = to_lvds_encoder(&encoder->base);
 	enum intel_display_power_domain power_domain;
 	u32 tmp;
+	bool ret;
 
 	power_domain = intel_display_port_power_domain(encoder);
-	if (!intel_display_power_is_enabled(dev_priv, power_domain))
+	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
 		return false;
 
+	ret = false;
+
 	tmp = I915_READ(lvds_encoder->reg);
 
 	if (!(tmp & LVDS_PORT_EN))
-		return false;
+		goto out;
 
 	if (HAS_PCH_CPT(dev))
 		*pipe = PORT_TO_PIPE_CPT(tmp);
 	else
 		*pipe = PORT_TO_PIPE(tmp);
 
-	return true;
+	ret = true;
+
+out:
+	intel_display_power_put(dev_priv, power_domain);
+
+	return ret;
 }
 
 static void intel_lvds_get_config(struct intel_encoder *encoder,
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index a234687792f0..b28c29f20e75 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2829,7 +2829,10 @@ void skl_ddb_get_hw_state(struct drm_i915_private *dev_priv,
 	memset(ddb, 0, sizeof(*ddb));
 
 	for_each_pipe(dev_priv, pipe) {
-		if (!intel_display_power_is_enabled(dev_priv, POWER_DOMAIN_PIPE(pipe)))
+		enum intel_display_power_domain power_domain;
+
+		power_domain = POWER_DOMAIN_PIPE(pipe);
+		if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
 			continue;
 
 		for_each_plane(dev_priv, pipe, plane) {
@@ -2841,6 +2844,8 @@ void skl_ddb_get_hw_state(struct drm_i915_private *dev_priv,
 		val = I915_READ(CUR_BUF_CFG(pipe));
 		skl_ddb_entry_init_from_hw(&ddb->plane[pipe][PLANE_CURSOR],
 					   val);
+
+		intel_display_power_put(dev_priv, power_domain);
 	}
 }
 
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index ddbdbffe829a..678ed3475d7e 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -470,6 +470,43 @@ static void gen9_set_dc_state_debugmask_memory_up(
 	}
 }
 
+static void gen9_write_dc_state(struct drm_i915_private *dev_priv,
+				u32 state)
+{
+	int rewrites = 0;
+	int rereads = 0;
+	u32 v;
+
+	I915_WRITE(DC_STATE_EN, state);
+
+	/* It has been observed that disabling the dc6 state sometimes
+	 * doesn't stick and dmc keeps returning old value. Make sure
+	 * the write really sticks enough times and also force rewrite until
+	 * we are confident that state is exactly what we want.
+	 */
+	do  {
+		v = I915_READ(DC_STATE_EN);
+
+		if (v != state) {
+			I915_WRITE(DC_STATE_EN, state);
+			rewrites++;
+			rereads = 0;
+		} else if (rereads++ > 5) {
+			break;
+		}
+
+	} while (rewrites < 100);
+
+	if (v != state)
+		DRM_ERROR("Writing dc state to 0x%x failed, now 0x%x\n",
+			  state, v);
+
+	/* Most of the times we need one retry, avoid spam */
+	if (rewrites > 1)
+		DRM_DEBUG_KMS("Rewrote dc state to 0x%x %d times\n",
+			      state, rewrites);
+}
+
 static void gen9_set_dc_state(struct drm_i915_private *dev_priv, uint32_t state)
 {
 	uint32_t val;
@@ -494,10 +531,18 @@ static void gen9_set_dc_state(struct drm_i915_private *dev_priv, uint32_t state)
 	val = I915_READ(DC_STATE_EN);
 	DRM_DEBUG_KMS("Setting DC state from %02x to %02x\n",
 		      val & mask, state);
+
+	/* Check if DMC is ignoring our DC state requests */
+	if ((val & mask) != dev_priv->csr.dc_state)
+		DRM_ERROR("DC state mismatch (0x%x -> 0x%x)\n",
+			  dev_priv->csr.dc_state, val & mask);
+
 	val &= ~mask;
 	val |= state;
-	I915_WRITE(DC_STATE_EN, val);
-	POSTING_READ(DC_STATE_EN);
+
+	gen9_write_dc_state(dev_priv, val);
+
+	dev_priv->csr.dc_state = val & mask;
 }
 
 void bxt_enable_dc9(struct drm_i915_private *dev_priv)
@@ -1442,6 +1487,22 @@ static void chv_pipe_power_well_disable(struct drm_i915_private *dev_priv,
 	chv_set_pipe_power_well(dev_priv, power_well, false);
 }
 
+static void
+__intel_display_power_get_domain(struct drm_i915_private *dev_priv,
+				 enum intel_display_power_domain domain)
+{
+	struct i915_power_domains *power_domains = &dev_priv->power_domains;
+	struct i915_power_well *power_well;
+	int i;
+
+	for_each_power_well(i, power_well, BIT(domain), power_domains) {
+		if (!power_well->count++)
+			intel_power_well_enable(dev_priv, power_well);
+	}
+
+	power_domains->domain_use_count[domain]++;
+}
+
 /**
  * intel_display_power_get - grab a power domain reference
  * @dev_priv: i915 device instance
@@ -1457,24 +1518,53 @@ static void chv_pipe_power_well_disable(struct drm_i915_private *dev_priv,
 void intel_display_power_get(struct drm_i915_private *dev_priv,
 			     enum intel_display_power_domain domain)
 {
-	struct i915_power_domains *power_domains;
-	struct i915_power_well *power_well;
-	int i;
+	struct i915_power_domains *power_domains = &dev_priv->power_domains;
 
 	intel_runtime_pm_get(dev_priv);
 
-	power_domains = &dev_priv->power_domains;
+	mutex_lock(&power_domains->lock);
+
+	__intel_display_power_get_domain(dev_priv, domain);
+
+	mutex_unlock(&power_domains->lock);
+}
+
+/**
+ * intel_display_power_get_if_enabled - grab a reference for an enabled display power domain
+ * @dev_priv: i915 device instance
+ * @domain: power domain to reference
+ *
+ * This function grabs a power domain reference for @domain and ensures that the
+ * power domain and all its parents are powered up. Therefore users should only
+ * grab a reference to the innermost power domain they need.
+ *
+ * Any power domain reference obtained by this function must have a symmetric
+ * call to intel_display_power_put() to release the reference again.
+ */
+bool intel_display_power_get_if_enabled(struct drm_i915_private *dev_priv,
+					enum intel_display_power_domain domain)
+{
+	struct i915_power_domains *power_domains = &dev_priv->power_domains;
+	bool is_enabled;
+
+	if (!intel_runtime_pm_get_if_in_use(dev_priv))
+		return false;
 
 	mutex_lock(&power_domains->lock);
 
-	for_each_power_well(i, power_well, BIT(domain), power_domains) {
-		if (!power_well->count++)
-			intel_power_well_enable(dev_priv, power_well);
+	if (__intel_display_power_is_enabled(dev_priv, domain)) {
+		__intel_display_power_get_domain(dev_priv, domain);
+		is_enabled = true;
+	} else {
+		is_enabled = false;
 	}
 
-	power_domains->domain_use_count[domain]++;
-
 	mutex_unlock(&power_domains->lock);
+
+	if (!is_enabled)
+		intel_runtime_pm_put(dev_priv);
+
+	return is_enabled;
 }
 
 /**
@@ -2246,6 +2336,43 @@ void intel_runtime_pm_get(struct drm_i915_private *dev_priv)
 }
 
 /**
+ * intel_runtime_pm_get_if_in_use - grab a runtime pm reference if device in use
+ * @dev_priv: i915 device instance
+ *
+ * This function grabs a device-level runtime pm reference if the device is
+ * already in use and ensures that it is powered up.
+ *
+ * Any runtime pm reference obtained by this function must have a symmetric
+ * call to intel_runtime_pm_put() to release the reference again.
+ */
+bool intel_runtime_pm_get_if_in_use(struct drm_i915_private *dev_priv)
+{
+	struct drm_device *dev = dev_priv->dev;
+	struct device *device = &dev->pdev->dev;
+	int ret;
+
+	if (!IS_ENABLED(CONFIG_PM))
+		return true;
+
+	ret = pm_runtime_get_if_in_use(device);
+
+	/*
+	 * In cases runtime PM is disabled by the RPM core and we get an
+	 * -EINVAL return value we are not supposed to call this function,
+	 * since the power state is undefined. This applies atm to the
+	 * late/early system suspend/resume handlers.
+	 */
+	WARN_ON_ONCE(ret < 0);
+	if (ret <= 0)
+		return false;
+
+	atomic_inc(&dev_priv->pm.wakeref_count);
+	assert_rpm_wakelock_held(dev_priv);
+
+	return true;
+}
+
+/**
  * intel_runtime_pm_get_noresume - grab a runtime pm reference
  * @dev_priv: i915 device instance
  *