drm/i915: Recognise non-VGA display devices
Starting with SandyBridge (though possible with earlier hacked BIOSes),
the BIOS may initialise the IGFX as secondary to a discrete GPU. Prior,
it would simply disable the integrated GPU. So we adjust our PCI class
mask to match any DISPLAY_CLASS device.
In such a configuration, the IGFX is not a primary VGA controller and
so should not take part in VGA arbitration, and the error return from
vga_client_register() is expected.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 6658981..17bd766 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1215,9 +1215,15 @@
if (ret)
DRM_INFO("failed to find VBIOS tables\n");
- /* if we have > 1 VGA cards, then disable the radeon VGA resources */
+ /* If we have > 1 VGA cards, then we need to arbitrate access
+ * to the common VGA resources.
+ *
+ * If we are a secondary display controller (!PCI_DISPLAY_CLASS_VGA),
+ * then we do not take part in VGA arbitration and the
+ * vga_client_register() fails with -ENODEV.
+ */
ret = vga_client_register(dev->pdev, dev, NULL, i915_vga_set_decode);
- if (ret)
+ if (ret && ret != -ENODEV)
goto cleanup_ringbuffer;
intel_register_dsm_handler();