Re: [PATCH] drm/i915: kick any firmware framebuffers before claiming the gtt

[Jani Nikula <jani.nikula@linux.intel.com>]

On Mon, 11 Jun 2012, Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
> Especially vesafb likes to map everything as uc- (yikes), and if that
> mapping hangs around still while we try to map the gtt as wc the
> kernel will downgrade our request to uc-, resulting in abyssal
> performance.
>
> Unfortunately we can't do this as early as readon does (i.e. as the
> first thing we do when initializing the hw) because our fb/mmio space
> region moves around on a per-gen basis. So I've had to move it below
> the gtt initialization, but that seems to work, too. The important
> thing is that we do this before we set up the gtt wc mapping.
>
> Now an altogether different question is why people compile their
> kernels with vesafb enabled, but I guess making things just work isn't
> bad per se ...
>
> Reported-and-tested-by: "Kilarski, Bernard R" <bernard.r.kilarski@intel.com>
> Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> ---
>  drivers/gpu/drm/i915/i915_dma.c |   35 ++++++++++++++++++++++++++++-------
>  1 file changed, 28 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
> index 262a74d..6be01c8 100644
> --- a/drivers/gpu/drm/i915/i915_dma.c
> +++ b/drivers/gpu/drm/i915/i915_dma.c
> @@ -1401,6 +1401,25 @@ i915_mtrr_setup(struct drm_i915_private *dev_priv, unsigned long base,
>  	}
>  }
>  
> +static void i915_kick_out_firmware_fb(struct drm_i915_private *dev_priv)
> +{
> +	struct apertures_struct *ap;
> +	struct pci_dev *pdev = dev_priv->dev->pdev;
> +	bool primary = false;
> +
> +	ap = alloc_apertures(1);
> +	ap->ranges[0].base = dev_priv->dev->agp->base;
> +	ap->ranges[0].size =
> +		dev_priv->mm.gtt->gtt_mappable_entries << PAGE_SHIFT;
> +
> +#ifdef CONFIG_X86
> +	primary = pdev->resource[PCI_ROM_RESOURCE].flags & IORESOURCE_ROM_SHADOW;
> +#endif
> +
> +	remove_conflicting_framebuffers(ap, "radeondrmfb", primary);
> +	kfree(ap);
> +}
> +
>  /**
>   * i915_driver_load - setup chip and create an initial config
>   * @dev: DRM device
> @@ -1446,6 +1465,15 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
>  		goto free_priv;
>  	}
>  
> +	dev_priv->mm.gtt = intel_gtt_get();
> +	if (!dev_priv->mm.gtt) {
> +		DRM_ERROR("Failed to initialize GTT\n");
> +		ret = -ENODEV;
> +		goto out_rmmap;
> +	}

Hi Daniel, the error handling goes wrong with this code move, at least
goto out_rmmap is wrong. Did not check much else in the patch.

BR,
Jani.



> +
> +	i915_kick_out_firmware_fb(dev_priv);
> +
>  	pci_set_master(dev->pdev);
>  
>  	/* overlay on gen2 is broken and can't address above 1G */
> @@ -1471,13 +1499,6 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
>  		goto put_bridge;
>  	}
>  
> -	dev_priv->mm.gtt = intel_gtt_get();
> -	if (!dev_priv->mm.gtt) {
> -		DRM_ERROR("Failed to initialize GTT\n");
> -		ret = -ENODEV;
> -		goto out_rmmap;
> -	}
> -
>  	aperture_size = dev_priv->mm.gtt->gtt_mappable_entries << PAGE_SHIFT;
>  
>  	dev_priv->mm.gtt_mapping =
> -- 
> 1.7.10
>
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