[Intel-gfx] [PATCH 02/10] drm/i915: Support PCH no display

[Ben Widawsky]

GEN supports a fusing option which subtracts the PCH display (making the
CPU display also useless). In this configuration MMIO which gets decoded
to a certain range will hang the CPU.

For us, this is sort of the equivalent of having no pipes, and we can
easily modify some code to not do certain things with no pipes.

Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
 drivers/gpu/drm/i915/i915_dma.c      | 20 ++++++++++++++------
 drivers/gpu/drm/i915/intel_crt.c     |  3 +++
 drivers/gpu/drm/i915/intel_display.c | 10 ++++++++--
 drivers/gpu/drm/i915/intel_fb.c      |  3 +++
 drivers/gpu/drm/i915/intel_overlay.c |  3 +++
 5 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index ebcfe2e..d925504 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1322,6 +1322,10 @@ static int i915_load_modeset_init(struct drm_device *dev)
 	/* Always safe in the mode setting case. */
 	/* FIXME: do pre/post-mode set stuff in core KMS code */
 	dev->vblank_disable_allowed = 1;
+	if (INTEL_INFO(dev)->num_pipes == 0) {
+		dev_priv->mm.suspended = 0;
+		return 0;
+	}
 
 	ret = intel_fbdev_init(dev);
 	if (ret)
@@ -1630,9 +1634,11 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 	mutex_init(&dev_priv->rps.hw_lock);
 	mutex_init(&dev_priv->modeset_restore_lock);
 
-	ret = drm_vblank_init(dev, INTEL_INFO(dev)->num_pipes);
-	if (ret)
-		goto out_gem_unload;
+	if (INTEL_INFO(dev)->num_pipes) {
+		ret = drm_vblank_init(dev, INTEL_INFO(dev)->num_pipes);
+		if (ret)
+			goto out_gem_unload;
+	}
 
 	/* Start out suspended */
 	dev_priv->mm.suspended = 1;
@@ -1647,9 +1653,11 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 
 	i915_setup_sysfs(dev);
 
-	/* Must be done after probing outputs */
-	intel_opregion_init(dev);
-	acpi_video_register();
+	if (INTEL_INFO(dev)->num_pipes) {
+		/* Must be done after probing outputs */
+		intel_opregion_init(dev);
+		acpi_video_register();
+	}
 
 	if (IS_GEN5(dev))
 		intel_gpu_ips_init(dev_priv);
diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index cfc9687..e794c6c 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -736,6 +736,9 @@ void intel_crt_init(struct drm_device *dev)
 	if (dmi_check_system(intel_no_crt))
 		return;
 
+	if (INTEL_INFO(dev)->num_pipes == 0)
+		return;
+
 	crt = kzalloc(sizeof(struct intel_crt), GFP_KERNEL);
 	if (!crt)
 		return;
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 23379e7..d6dbffd 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -7682,6 +7682,9 @@ intel_modeset_check_state(struct drm_device *dev)
 	struct intel_encoder *encoder;
 	struct intel_connector *connector;
 
+	if (INTEL_INFO(dev)->num_pipes == 0)
+		return;
+
 	list_for_each_entry(connector, &dev->mode_config.connector_list,
 			    base.head) {
 		/* This also checks the encoder/connector hw state with the
@@ -8326,7 +8329,9 @@ static void intel_setup_outputs(struct drm_device *dev)
 	if (!(HAS_DDI(dev) && (I915_READ(DDI_BUF_CTL(PORT_A)) & DDI_A_4_LANES)))
 		intel_crt_init(dev);
 
-	if (HAS_DDI(dev)) {
+	if (INTEL_INFO(dev)->num_pipes == 0) {
+		DRM_DEBUG_KMS("Skipping output detection\n");
+	} else if (HAS_DDI(dev)) {
 		int found;
 
 		/* Haswell uses DDI functions to detect digital outputs */
@@ -8443,7 +8448,8 @@ static void intel_setup_outputs(struct drm_device *dev)
 
 	intel_init_pch_refclk(dev);
 
-	drm_helper_move_panel_connectors_to_head(dev);
+	if (INTEL_INFO(dev)->num_pipes)
+		drm_helper_move_panel_connectors_to_head(dev);
 }
 
 static void intel_user_framebuffer_destroy(struct drm_framebuffer *fb)
diff --git a/drivers/gpu/drm/i915/intel_fb.c b/drivers/gpu/drm/i915/intel_fb.c
index dcdb1d3..5f825c2 100644
--- a/drivers/gpu/drm/i915/intel_fb.c
+++ b/drivers/gpu/drm/i915/intel_fb.c
@@ -295,6 +295,9 @@ void intel_fb_restore_mode(struct drm_device *dev)
 	struct drm_mode_config *config = &dev->mode_config;
 	struct drm_plane *plane;
 
+	if (!INTEL_INFO(dev)->num_pipes)
+		return;
+
 	drm_modeset_lock_all(dev);
 
 	ret = drm_fb_helper_restore_fbdev_mode(&dev_priv->fbdev->helper);
diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c
index 67a2501..e7fbf2e 100644
--- a/drivers/gpu/drm/i915/intel_overlay.c
+++ b/drivers/gpu/drm/i915/intel_overlay.c
@@ -1323,6 +1323,9 @@ void intel_setup_overlay(struct drm_device *dev)
 	if (!HAS_OVERLAY(dev))
 		return;
 
+	if (INTEL_INFO(dev)->num_pipes == 0)
+		return;
+
 	overlay = kzalloc(sizeof(struct intel_overlay), GFP_KERNEL);
 	if (!overlay)
 		return;
-- 
1.8.1.5