Re: [PATCH 5/8] drm/i915: Wrap the preallocated BIOS framebuffer and preserve for KMS fbcon

[Imre Deak <imre.deak@intel.com>]

On Wed, 2013-02-06 at 11:10 +0000, Chris Wilson wrote:
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
> ---
>  drivers/gpu/drm/i915/i915_dma.c      |    8 +-
>  drivers/gpu/drm/i915/i915_drv.h      |    2 +-
>  drivers/gpu/drm/i915/intel_display.c |   14 +-
>  drivers/gpu/drm/i915/intel_drv.h     |    4 +
>  drivers/gpu/drm/i915/intel_fb.c      |  305 +++++++++++++++++++++++++++++++---
>  5 files changed, 306 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
> index 4fa6beb..f2b7db7 100644
> --- a/drivers/gpu/drm/i915/i915_dma.c
> +++ b/drivers/gpu/drm/i915/i915_dma.c
> @@ -1273,6 +1273,7 @@ static const struct vga_switcheroo_client_ops i915_switcheroo_ops = {
>  static int i915_load_modeset_init(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
> +	bool was_vga_enabled;
>  	int ret;
>  
>  	ret = intel_parse_bios(dev);
> @@ -1309,7 +1310,11 @@ static int i915_load_modeset_init(struct drm_device *dev)
>  
>  	/* Important: The output setup functions called by modeset_init need
>  	 * working irqs for e.g. gmbus and dp aux transfers. */
> -	intel_modeset_init(dev);
> +	intel_modeset_init(dev, &was_vga_enabled);
> +
> +	/* Wrap existing BIOS mode configuration prior to GEM takeover */
> +	if (!was_vga_enabled)
> +		intel_fbdev_init_bios(dev);
>  
>  	ret = i915_gem_init(dev);
>  	if (ret)
> @@ -1323,6 +1328,7 @@ static int i915_load_modeset_init(struct drm_device *dev)
>  	/* FIXME: do pre/post-mode set stuff in core KMS code */
>  	dev->vblank_disable_allowed = 1;
>  
> +	/* Install a default KMS/GEM fbcon if we failed to wrap the BIOS fb */
>  	ret = intel_fbdev_init(dev);
>  	if (ret)
>  		goto cleanup_gem;
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index fd8a495..6f4afbf 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1814,7 +1814,7 @@ static inline void intel_unregister_dsm_handler(void) { return; }
>  
>  /* modesetting */
>  extern void intel_modeset_init_hw(struct drm_device *dev);
> -extern void intel_modeset_init(struct drm_device *dev);
> +extern void intel_modeset_init(struct drm_device *dev, bool *was_vga_enabled);
>  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);
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 8f9cdd7..7c4c7d5 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -8698,12 +8698,17 @@ static void intel_init_quirks(struct drm_device *dev)
>  }
>  
>  /* Disable the VGA plane that we never use */
> -static void i915_disable_vga(struct drm_device *dev)
> +static bool i915_disable_vga(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
> +	bool was_enabled;
>  	u8 sr1;
>  	u32 vga_reg = i915_vgacntrl_reg(dev);
>  
> +	was_enabled = !(I915_READ(vga_reg) & VGA_DISP_DISABLE);
> +	DRM_DEBUG_KMS("VGA output is currently %s\n",
> +		      was_enabled ? "enabled" : "disabled");
> +
>  	vga_get_uninterruptible(dev->pdev, VGA_RSRC_LEGACY_IO);
>  	outb(SR01, VGA_SR_INDEX);
>  	sr1 = inb(VGA_SR_DATA);
> @@ -8713,6 +8718,8 @@ static void i915_disable_vga(struct drm_device *dev)
>  
>  	I915_WRITE(vga_reg, VGA_DISP_DISABLE);
>  	POSTING_READ(vga_reg);
> +
> +	return was_enabled;
>  }
>  
>  void intel_modeset_init_hw(struct drm_device *dev)
> @@ -8728,7 +8735,8 @@ void intel_modeset_init_hw(struct drm_device *dev)
>  	mutex_unlock(&dev->struct_mutex);
>  }
>  
> -void intel_modeset_init(struct drm_device *dev)
> +void intel_modeset_init(struct drm_device *dev,
> +			bool *was_vga_enabled)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  	int i, ret;
> @@ -8775,7 +8783,7 @@ void intel_modeset_init(struct drm_device *dev)
>  	intel_pch_pll_init(dev);
>  
>  	/* Just disable it once at startup */
> -	i915_disable_vga(dev);
> +	*was_vga_enabled = i915_disable_vga(dev);
>  	intel_setup_outputs(dev);
>  
>  	/* Just in case the BIOS is doing something questionable. */
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 07d95a1..985e9dd 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -146,6 +146,8 @@ struct intel_fbdev {
>  	struct intel_framebuffer ifb;
>  	struct list_head fbdev_list;
>  	struct drm_display_mode *our_mode;
> +	bool stolen;
> +	int preferred_bpp;
>  };
>  
>  struct intel_encoder {
> @@ -212,6 +214,7 @@ struct intel_crtc {
>  	enum plane plane;
>  	enum transcoder cpu_transcoder;
>  	u8 lut_r[256], lut_g[256], lut_b[256];
> +	bool mode_valid;
>  	/*
>  	 * Whether the crtc and the connected output pipeline is active. Implies
>  	 * that crtc->enabled is set, i.e. the current mode configuration has
> @@ -612,6 +615,7 @@ extern int intel_framebuffer_init(struct drm_device *dev,
>  				  struct intel_framebuffer *ifb,
>  				  struct drm_mode_fb_cmd2 *mode_cmd,
>  				  struct drm_i915_gem_object *obj);
> +extern void intel_fbdev_init_bios(struct drm_device *dev);
>  extern int intel_fbdev_init(struct drm_device *dev);
>  extern void intel_fbdev_initial_config(struct drm_device *dev);
>  extern void intel_fbdev_fini(struct drm_device *dev);
> diff --git a/drivers/gpu/drm/i915/intel_fb.c b/drivers/gpu/drm/i915/intel_fb.c
> index de0ac4c..ca6c8e6 100644
> --- a/drivers/gpu/drm/i915/intel_fb.c
> +++ b/drivers/gpu/drm/i915/intel_fb.c
> @@ -131,7 +131,6 @@ static int intelfb_create(struct intel_fbdev *ifbdev,
>  	struct drm_device *dev = ifbdev->helper.dev;
>  	struct drm_mode_fb_cmd2 mode_cmd = { 0 };
>  	struct drm_i915_gem_object *obj;
> -	struct fb_info *info;
>  	int size, ret;
>  
>  	/* we don't do packed 24bpp */
> @@ -176,14 +175,7 @@ static int intelfb_create(struct intel_fbdev *ifbdev,
>  		      mode_cmd.width, mode_cmd.height,
>  		      obj->gtt_offset, obj);
>  
> -	info = intelfb_create_info(ifbdev);
> -	if (info == NULL) {
> -		ret = -ENOMEM;
> -		goto out_unpin;
> -	}
> -
>  	mutex_unlock(&dev->struct_mutex);
> -	vga_switcheroo_client_fb_set(dev->pdev, info);
>  	return 0;
>  
>  out_unpin:
> @@ -200,17 +192,92 @@ static int intel_fb_find_or_create_single(struct drm_fb_helper *helper,
>  {
>  	struct intel_fbdev *ifbdev = (struct intel_fbdev *)helper;
>  	int new_fb = 0;
> -	int ret;
>  
>  	if (!helper->fb) {
> -		ret = intelfb_create(ifbdev, sizes);
> -		if (ret)
> -			return ret;
> +		struct fb_info *info;
> +
> +		if (!ifbdev->stolen) {
> +			int ret = intelfb_create(ifbdev, sizes);
> +			if (ret)
> +				return ret;
> +		}
> +
> +		info = intelfb_create_info(ifbdev);
> +		if (info == NULL) {
> +			DRM_DEBUG_KMS("fb creation failed\n");
> +			return -ENOMEM;
> +		}
> +		vga_switcheroo_client_fb_set(helper->dev->pdev, info);
> +
>  		new_fb = 1;
>  	}
> +
>  	return new_fb;
>  }
>  
> +static struct drm_fb_helper_crtc *
> +intel_fb_helper_crtc(struct drm_fb_helper *fb_helper, struct drm_crtc *crtc)
> +{
> +	int i;
> +
> +	for (i = 0; i < fb_helper->crtc_count; i++)
> +		if (fb_helper->crtc_info[i].mode_set.crtc == crtc)
> +			return &fb_helper->crtc_info[i];
> +
> +	return NULL;
> +}
> +
> +static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
> +				    struct drm_fb_helper_crtc **crtcs,
> +				    struct drm_display_mode **modes,
> +				    bool *enabled, int width, int height)
> +{
> +	int i;
> +
> +	for (i = 0; i < fb_helper->connector_count; i++) {
> +		struct drm_connector *connector;
> +		struct drm_encoder *encoder;
> +
> +		connector = fb_helper->connector_info[i]->connector;
> +		if (!enabled[i]) {
> +			DRM_DEBUG_KMS("connector %d not enabled, skipping\n",
> +				      connector->base.id);
> +			continue;
> +		}
> +
> +		encoder = connector->encoder;
> +		if (!encoder || !encoder->crtc) {
> +			DRM_DEBUG_KMS("connector %d has no encoder or crtc, skipping\n",
> +				      connector->base.id);
> +			continue;
> +		}
> +
> +		if (WARN_ON(!encoder->crtc->enabled)) {
> +			DRM_DEBUG_KMS("connector %s on crtc %d has inconsistent state, aborting\n",
> +				      drm_get_connector_name(connector),
> +				      encoder->crtc->base.id);
> +			return false;
> +		}
> +
> +		if (!to_intel_crtc(encoder->crtc)->mode_valid) {
> +			DRM_DEBUG_KMS("connector %s on crtc %d has an invalid mode, aborting\n",
> +				      drm_get_connector_name(connector),
> +				      encoder->crtc->base.id);
> +			return false;
> +		}
> +
> +		modes[i] = &encoder->crtc->mode;

I might be missing something, but I can't see how crtc->mode will be
valid at this point. We'll get here through
intel_fb_initial_config()->drm_setup_crtcs() but as I understand
crtc->mode will only be set afterwards through
intel_fb_initial_config()->drm_fb_helper_single_fb_probe().

At least testing on my ILK I get here with mode_valid=false.

--Imre