[PATCH 1/4] drm/i915: Do not enable package C8 on unsupported hardware

[Paulo Zanoni <przanoni@gmail.com>]

From: Chris Wilson <chris@chris-wilson.co.uk>

If the hardware does not support package C8, then do not even schedule
work to enable it. Thereby we can eliminate a bunch of dangerous work.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h      |  1 +
 drivers/gpu/drm/i915/intel_display.c | 15 +++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 2c1921d..a28a676 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1790,6 +1790,7 @@ struct drm_i915_file_private {
 #define HAS_POWER_WELL(dev)	(IS_HASWELL(dev))
 #define HAS_FPGA_DBG_UNCLAIMED(dev)	(INTEL_INFO(dev)->has_fpga_dbg)
 #define HAS_PSR(dev)		(IS_HASWELL(dev))
+#define HAS_PC8(dev)		(IS_HASWELL(dev)) /* XXX HSW:ULX */
 
 #define INTEL_PCH_DEVICE_ID_MASK		0xff00
 #define INTEL_PCH_IBX_DEVICE_ID_TYPE		0x3b00
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index f0b42bc..14327ff 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6473,6 +6473,9 @@ static void __hsw_disable_package_c8(struct drm_i915_private *dev_priv)
 
 void hsw_enable_package_c8(struct drm_i915_private *dev_priv)
 {
+	if (!HAS_PC8(dev_priv->dev))
+		return;
+
 	mutex_lock(&dev_priv->pc8.lock);
 	__hsw_enable_package_c8(dev_priv);
 	mutex_unlock(&dev_priv->pc8.lock);
@@ -6480,6 +6483,9 @@ void hsw_enable_package_c8(struct drm_i915_private *dev_priv)
 
 void hsw_disable_package_c8(struct drm_i915_private *dev_priv)
 {
+	if (!HAS_PC8(dev_priv->dev))
+		return;
+
 	mutex_lock(&dev_priv->pc8.lock);
 	__hsw_disable_package_c8(dev_priv);
 	mutex_unlock(&dev_priv->pc8.lock);
@@ -6517,6 +6523,9 @@ static void hsw_update_package_c8(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	bool allow;
 
+	if (!HAS_PC8(dev_priv->dev))
+		return;
+
 	if (!i915_enable_pc8)
 		return;
 
@@ -6540,6 +6549,9 @@ done:
 
 static void hsw_package_c8_gpu_idle(struct drm_i915_private *dev_priv)
 {
+	if (!HAS_PC8(dev_priv->dev))
+		return;
+
 	if (!dev_priv->pc8.gpu_idle) {
 		dev_priv->pc8.gpu_idle = true;
 		hsw_enable_package_c8(dev_priv);
@@ -6548,6 +6560,9 @@ static void hsw_package_c8_gpu_idle(struct drm_i915_private *dev_priv)
 
 static void hsw_package_c8_gpu_busy(struct drm_i915_private *dev_priv)
 {
+	if (!HAS_PC8(dev_priv->dev))
+		return;
+
 	if (dev_priv->pc8.gpu_idle) {
 		dev_priv->pc8.gpu_idle = false;
 		hsw_disable_package_c8(dev_priv);
-- 
1.8.3.1