drm/nvc0/pfifo: semi-handle a couple more irqs

And also, don't disable PFIFO IRQs completely whenever we recieve one,
just when we don't know about it already.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nvc0_fifo.c

@@ -418,6 +418,12 @@ nvc0_fifo_isr(struct drm_device *dev)
 {
 	u32 stat = nv_rd32(dev, 0x002100);
 
+	if (stat & 0x00000100) {
+		NV_INFO(dev, "PFIFO: unknown status 0x00000100\n");
+		nv_wr32(dev, 0x002100, 0x00000100);
+		stat &= ~0x00000100;
+	}
+
 	if (stat & 0x10000000) {
 		u32 units = nv_rd32(dev, 0x00259c);
 		u32 u = units;
@@ -446,10 +452,15 @@ nvc0_fifo_isr(struct drm_device *dev)
 		stat &= ~0x20000000;
 	}
 
+	if (stat & 0x40000000) {
+		NV_INFO(dev, "PFIFO: unknown status 0x40000000\n");
+		nv_mask(dev, 0x002a00, 0x00000000, 0x00000000);
+		stat &= ~0x40000000;
+	}
+
 	if (stat) {
 		NV_INFO(dev, "PFIFO: unhandled status 0x%08x\n", stat);
 		nv_wr32(dev, 0x002100, stat);
+		nv_wr32(dev, 0x002140, 0);
 	}
-
-	nv_wr32(dev, 0x2140, 0);
 }