drm: add test for AGP devices and driver override for it.

Added device_is_agp callback to drm_driver.  This function is called by the
platform-specific drm_device_is_agp function.  Added implementation of this
function the the Linux-specific portion of the MGA driver to detect PCI G450
cards.  Added code to the Linux-specific portion of the generic DRM layer to
not initialize AGP infrastructure if the card is not AGP (this matches what
already existed in BSD).

Fix up i810/i830 and i915 drivers to always return AGP as they don't always
report the capability.

Fix the MGA to not report AGP for a card that has an AGP chip behind a PCI
bridge.

From: Ian Romanick, Dave Airlie, Alan Hourihane
Signed-off-by: Dave Airlie <airlied@linux.ie>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/char/drm/i830_drv.c b/drivers/char/drm/i830_drv.c
index bc36be76b8b2..0da9cd19919e 100644
--- a/drivers/char/drm/i830_drv.c
+++ b/drivers/char/drm/i830_drv.c
@@ -88,6 +88,7 @@ static struct drm_driver driver = {
         .dev_priv_size = sizeof(drm_i830_buf_priv_t),
         .pretakedown = i830_driver_pretakedown,
         .prerelease = i830_driver_prerelease,
+        .device_is_agp = i830_driver_device_is_agp,
         .release = i830_driver_release,
         .dma_quiescent = i830_driver_dma_quiescent,
         .reclaim_buffers = i830_reclaim_buffers,