[Intel-gfx] Why set fb_base twice?

[Jet Chen]

Hi,
I was reading drm code, and found a interesting thing. In "i915_dma.c ::
i915_load_modeset_init()", we set the fb base address:

static int i915_load_modeset_init(struct drm_device *dev,

  unsigned long prealloc_start,

  unsigned long prealloc_size,

  unsigned long agp_size)

{

struct drm_i915_private *dev_priv = dev->dev_private;

int fb_bar = IS_I9XX(dev) ? 2 : 0;

int ret = 0;


> dev->mode_config.fb_base = pci_resource_start(dev->pdev, fb_bar) &

0xff000000;


after that, "i915_load_modeset_init()" calls "intel_display.c ::
intel_modeset_init()" . In "intel_modeset_init()", we set fb_base once
again!

/* set memory base */

if (IS_I9XX(dev))

dev->mode_config.fb_base = pci_resource_start(dev->pdev, 2);

else

dev->mode_config.fb_base = pci_resource_start(dev->pdev, 0);


Does it make any sense that set the same fb_base twice, or we can remove one
of them?

-- 
Jet Chen
Platform Engineering Solution - IT Flex Services,
Intel Asia-Pacific R&D Center Ltd,
+86 6116 5665
jet.chen at intel.com
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