[PATCH] drm/i915: Check disable display module parameter earlier

[Mika Kahola]

At least in Coffee Lake it happens that we start initiliazing audio when
no display is connected. This was discovered by CI when running IGT test
case

drv_module_reload --r basic-no-display

The issue here is that the 'intel_device_info_runtime_init()' sets
num_pipes to 0 but before this happens the audio part has already started
to initialize itself. Later on the num_pipes is updated to 0 in
intel_device_info_runtime_init() and we hit that when audio part is digging
out ELD. This causes a warning in dmesg. To fix this issue, let's move
the check for disabled display module parameter earlier in the driver
initialization sequence.

Signed-off-by: Mika Kahola <mika.kahola at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c          | 5 +++++
 drivers/gpu/drm/i915/intel_device_info.c | 5 +----
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index e7e9e06..d26c2e6 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -886,6 +886,11 @@ static int i915_driver_init_early(struct drm_i915_private *dev_priv,
 	BUG_ON(device_info->gen > sizeof(device_info->gen_mask) * BITS_PER_BYTE);
 	device_info->gen_mask = BIT(device_info->gen - 1);
 
+	if (i915_modparams.disable_display) {
+		DRM_INFO("Display disabled (module parameter)\n");
+		device_info->num_pipes = 0;
+	}
+
 	spin_lock_init(&dev_priv->irq_lock);
 	spin_lock_init(&dev_priv->gpu_error.lock);
 	mutex_init(&dev_priv->backlight_lock);
diff --git a/drivers/gpu/drm/i915/intel_device_info.c b/drivers/gpu/drm/i915/intel_device_info.c
index db03d17..1414e2b 100644
--- a/drivers/gpu/drm/i915/intel_device_info.c
+++ b/drivers/gpu/drm/i915/intel_device_info.c
@@ -379,10 +379,7 @@ void intel_device_info_runtime_init(struct drm_i915_private *dev_priv)
 			info->num_sprites[pipe] = 1;
 	}
 
-	if (i915_modparams.disable_display) {
-		DRM_INFO("Display disabled (module parameter)\n");
-		info->num_pipes = 0;
-	} else if (info->num_pipes > 0 &&
+	if (info->num_pipes > 0 &&
 		   (IS_GEN7(dev_priv) || IS_GEN8(dev_priv)) &&
 		   HAS_PCH_SPLIT(dev_priv)) {
 		u32 fuse_strap = I915_READ(FUSE_STRAP);
-- 
2.7.4