gma500: Only register interrupt handler for poulsbo hardware

First step in adding proper irq handling. We'll start with poulsbo support so
make sure other chips don't touch drm_irq_install().
Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/gma500/psb_drv.c

@@ -368,7 +368,7 @@ static int psb_driver_load(struct drm_device *dev, unsigned long chipset)
 	PSB_WVDC32(0x00000000, PSB_INT_ENABLE_R);
 	PSB_WVDC32(0xFFFFFFFF, PSB_INT_MASK_R);
 	spin_unlock_irqrestore(&dev_priv->irqmask_lock, irqflags);
-	if (drm_core_check_feature(dev, DRIVER_MODESET))
+	if (IS_PSB(dev) && drm_core_check_feature(dev, DRIVER_MODESET))
 		drm_irq_install(dev);
 
 	dev->vblank_disable_allowed = 1;

drivers/gpu/drm/gma500/psb_drv.h

@@ -42,6 +42,7 @@ enum {
 	CHIP_MFLD_0130 = 3,		/* Medfield */
 };
 
+#define IS_PSB(dev) (((dev)->pci_device & 0xfffe) == 0x8108)
 #define IS_MRST(dev) (((dev)->pci_device & 0xfffc) == 0x4100)
 #define IS_MFLD(dev) (((dev)->pci_device & 0xfff8) == 0x0130)