[Intel-gfx] [PATCH 3/3] drm/i915: Disable all outputs early, before KMS takeover

[Ben Widawsky]

On Wed, Apr 13, 2011 at 09:28:25AM +0100, Chris Wilson 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 <penberg at kernel.org>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Tested-by: Daniel Vetter <daniel.vetter at ffwll.ch> (855GM)
> Tested-by: Pekka Enberg <penberg at 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
> ---
>  drivers/gpu/drm/i915/i915_dma.c      |   31 ++++++++++++++++++++++---------
>  drivers/gpu/drm/i915/i915_drv.h      |    1 +
>  drivers/gpu/drm/i915/intel_display.c |   17 +++++++++++------
>  3 files changed, 34 insertions(+), 15 deletions(-)
> 
> 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 5004724..8865ec1 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1265,6 +1265,7 @@ 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 e522c70..2183c4d 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -6504,6 +6504,9 @@ 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)
> @@ -7439,13 +7442,12 @@ 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);
> @@ -7454,12 +7456,15 @@ 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);
>  }

Reviewed-by: Ben Widawsky <ben at bwidawsk.net>