On Mon, 11 Jun 2012, Daniel Vetter <daniel.vetter at 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 at intel.com>
> Signed-Off-by: Daniel Vetter <daniel.vetter at 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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