drm/i915: Disable all outputs early, before KMS takeover

If the outputs are active and continuing to access the GATT when we
teardown the PTEs, then there is a potential for us to hang the GPU.
The hang tends to be a PGTBL_ER with either an invalid host access or
an invalid display plane fetch.

v2: Reorder IRQ initialisation to defer until after GEM is setup.

Reported-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Daniel Vetter <daniel.vetter@ffwll.ch> (855GM)
Tested-by: Pekka Enberg <penberg@kernel.org>
           # note that this doesn't fix the underlying problem of the
             PGTBL_ER and pipe underruns being reported immediately upon
             init on his 965GM MacBook
Reported-and-tested-by: Rick Bramley <richard.bramley@hp.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=35635
Reported-and-tested-by: Zdenek Kabelac <zdenek.kabelac@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=36048
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>

1 files changed, 22 insertions, 9 deletions

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 64c6f67..01ca0e9 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1176,11 +1176,11 @@ static bool i915_switcheroo_can_switch(struct pci_dev *pdev)
 	return can_switch;
 }
 
-static int i915_load_modeset_init(struct drm_device *dev)
+static int i915_load_gem_init(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	unsigned long prealloc_size, gtt_size, mappable_size;
-	int ret = 0;
+	int ret;
 
 	prealloc_size = dev_priv->mm.gtt->stolen_size;
 	gtt_size = dev_priv->mm.gtt->gtt_total_entries << PAGE_SHIFT;
@@ -1204,7 +1204,7 @@ static int i915_load_modeset_init(struct drm_device *dev)
 	ret = i915_gem_init_ringbuffer(dev);
 	mutex_unlock(&dev->struct_mutex);
 	if (ret)
-		goto out;
+		return ret;
 
 	/* Try to set up FBC with a reasonable compressed buffer size */
 	if (I915_HAS_FBC(dev) && i915_powersave) {
@@ -1222,6 +1222,13 @@ static int i915_load_modeset_init(struct drm_device *dev)
 
 	/* Allow hardware batchbuffers unless told otherwise. */
 	dev_priv->allow_batchbuffer = 1;
+	return 0;
+}
+
+static int i915_load_modeset_init(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	int ret;
 
 	ret = intel_parse_bios(dev);
 	if (ret)
@@ -1236,7 +1243,7 @@ static int i915_load_modeset_init(struct drm_device *dev)
 	 */
 	ret = vga_client_register(dev->pdev, dev, NULL, i915_vga_set_decode);
 	if (ret && ret != -ENODEV)
-		goto cleanup_ringbuffer;
+		goto out;
 
 	intel_register_dsm_handler();
 
@@ -1253,10 +1260,16 @@ static int i915_load_modeset_init(struct drm_device *dev)
 
 	intel_modeset_init(dev);
 
-	ret = drm_irq_install(dev);
+	ret = i915_load_gem_init(dev);
 	if (ret)
 		goto cleanup_vga_switcheroo;
 
+	intel_modeset_gem_init(dev);
+
+	ret = drm_irq_install(dev);
+	if (ret)
+		goto cleanup_gem;
+
 	/* Always safe in the mode setting case. */
 	/* FIXME: do pre/post-mode set stuff in core KMS code */
 	dev->vblank_disable_allowed = 1;
@@ -1274,14 +1287,14 @@ static int i915_load_modeset_init(struct drm_device *dev)
 
 cleanup_irq:
 	drm_irq_uninstall(dev);
+cleanup_gem:
+	mutex_lock(&dev->struct_mutex);
+	i915_gem_cleanup_ringbuffer(dev);
+	mutex_unlock(&dev->struct_mutex);
 cleanup_vga_switcheroo:
 	vga_switcheroo_unregister_client(dev->pdev);
 cleanup_vga_client:
 	vga_client_register(dev->pdev, NULL, NULL, NULL);
-cleanup_ringbuffer:
-	mutex_lock(&dev->struct_mutex);
-	i915_gem_cleanup_ringbuffer(dev);
-	mutex_unlock(&dev->struct_mutex);
 out:
 	return ret;
 }