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

Commit Message

Chris Wilson April 5, 2011, 2:34 p.m. UTC

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 <[e-mail]>
Signed-off-by: Chris Wilson <[e-mail]>
Tested-by: Daniel Vetter <[e-mail]> (855GM)
---
 drivers/gpu/drm/i915/i915_dma.c      |   31 ++++++++++++++++++++++---------
 drivers/gpu/drm/i915/i915_drv.h      |    1 +
 drivers/gpu/drm/i915/intel_display.c |   17 +++++++++++------
 drivers/gpu/drm/i915/intel_dp.c      |    9 +++++++++
 4 files changed, 43 insertions(+), 15 deletions(-)

Comments

Chris Wilson April 5, 2011, 3:32 p.m. UTC | #1

On Tue, 5 Apr 2011 18:11:37 +0300, Pekka Enberg <[e-mail]> wrote:
> Hi Chris,
> 
> On Tue, Apr 5, 2011 at 5:34 PM, Chris Wilson <[e-mail]> wrote:
> > 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 <[e-mail]>
> > Signed-off-by: Chris Wilson <[e-mail]>
> > Tested-by: Daniel Vetter <[e-mail]> (855GM)
> 
> I no longer get a blank screen after boot but flicker got more
> aggressive during boot (it calms down after I've logged in). I see
> tons of these in dmesg that don't appear with 2.6.39-rc1:

Well the PGTBL_ER is still there. I'm thinking it might worth a check to
see if that is asserted even before we start...

> [   10.175843] [drm:intel_update_fbc],
> [   10.183100] [drm:i915_driver_irq_handler], pipe A underrun
> [   10.185085] [drm:i915_driver_irq_handler], pipe A underrun
> [   10.186082] [drm:i915_driver_irq_handler], pipe A underrun
> [   10.187087] [drm:i915_driver_irq_handler], pipe A underrun
> [   10.189082] [drm:i915_driver_irq_handler], pipe A underrun
> [   10.190085] [drm:i915_driver_irq_handler], pipe A underrun

If I'm understanding the dmesg correctly, then these start even before we
setup the first crtc.

Whether that means we're not completely disabling all outputs or that we
set a register incorrectly I don't know. Comparing an intel_reg_dumper
with and without the patch applied might give a clue if it is a register
that is set differently due to the reordering.

The other question is of course whether you see those in 2.6.39-rc1 as
well... Probably not since they will correspond with the increased
flicker.
-Chris

Patch

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 7273037..b28e023 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;
 }
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 359ddce..60ebd79 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1268,6 +1268,7 @@  static inline void intel_unregister_dsm_handler(void) { return; }
 
 /* modesetting */
 extern void intel_modeset_init(struct drm_device *dev);
+extern void intel_modeset_gem_init(struct drm_device *dev);
 extern void intel_modeset_cleanup(struct drm_device *dev);
 extern int intel_modeset_vga_set_state(struct drm_device *dev, bool state);
 extern void i8xx_disable_fbc(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 432fc04..5c7385b 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6497,6 +6497,9 @@  static void intel_setup_outputs(struct drm_device *dev)
 	}
 
 	intel_panel_setup_backlight(dev);
+
+	/* disable all the possible outputs/crtcs before entering KMS mode */
+	drm_helper_disable_unused_functions(dev);
 }
 
 static void intel_user_framebuffer_destroy(struct drm_framebuffer *fb)
@@ -7432,13 +7435,12 @@  void intel_modeset_init(struct drm_device *dev)
 		intel_crtc_init(dev, i);
 	}
 
+	/* Just disable it once at startup */
+	i915_disable_vga(dev);
 	intel_setup_outputs(dev);
 
 	intel_enable_clock_gating(dev);
 
-	/* Just disable it once at startup */
-	i915_disable_vga(dev);
-
 	if (IS_IRONLAKE_M(dev)) {
 		ironlake_enable_drps(dev);
 		intel_init_emon(dev);
@@ -7447,12 +7449,15 @@  void intel_modeset_init(struct drm_device *dev)
 	if (IS_GEN6(dev))
 		gen6_enable_rps(dev_priv);
 
-	if (IS_IRONLAKE_M(dev))
-		ironlake_enable_rc6(dev);
-
 	INIT_WORK(&dev_priv->idle_work, intel_idle_update);
 	setup_timer(&dev_priv->idle_timer, intel_gpu_idle_timer,
 		    (unsigned long)dev);
+}
+
+void intel_modeset_gem_init(struct drm_device *dev)
+{
+	if (IS_IRONLAKE_M(dev))
+		ironlake_enable_rc6(dev);
 
 	intel_setup_overlay(dev);
 }
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 0daefca..6caeabb 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -218,7 +218,16 @@  intel_dp_mode_valid(struct drm_connector *connector,
 	if (!is_edp(intel_dp) &&
 	    (intel_dp_link_required(connector->dev, intel_dp, mode->clock)
 	     > intel_dp_max_data_rate(max_link_clock, max_lanes)))
+	{
+		DRM_DEBUG_KMS("mode exceeds DP bandwidth: required=%d, max=%d [clock=%d, lanes=%d]\n",
+			      intel_dp_link_required(connector->dev,
+						     intel_dp,
+						     mode->clock),
+			      intel_dp_max_data_rate(max_link_clock,
+						     max_lanes),
+			      max_link_clock, max_lanes);
 		return MODE_CLOCK_HIGH;
+	}
 
 	if (mode->clock < 10000)
 		return MODE_CLOCK_LOW;