drm/nouveau: handle fifo pusher errors better

The most important part of this change is that we now instruct PFIFO to
drop all pending fetches, rather than attempting to skip a single dword
and hope that things would magically sort themselves out - they usually
don't, and we end up with PFIFO being completely hung.

This commit also adds somewhat more useful logging when these exceptions
occur.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/nouveau_irq.c b/drivers/gpu/drm/nouveau/nouveau_irq.c
index a818306..6fd51a5 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_irq.c
+++ b/drivers/gpu/drm/nouveau/nouveau_irq.c
@@ -202,16 +202,45 @@ nouveau_fifo_irq_handler(struct drm_device *dev)
                }
 
                if (status & NV_PFIFO_INTR_DMA_PUSHER) {
-                       NV_INFO(dev, "PFIFO_DMA_PUSHER - Ch %d\n", chid);
+                       u32 get = nv_rd32(dev, 0x003244);
+                       u32 put = nv_rd32(dev, 0x003240);
+                       u32 push = nv_rd32(dev, 0x003220);
+                       u32 state = nv_rd32(dev, 0x003228);
+
+                       if (dev_priv->card_type == NV_50) {
+                               u32 ho_get = nv_rd32(dev, 0x003328);
+                               u32 ho_put = nv_rd32(dev, 0x003320);
+                               u32 ib_get = nv_rd32(dev, 0x003334);
+                               u32 ib_put = nv_rd32(dev, 0x003330);
+
+                               NV_INFO(dev, "PFIFO_DMA_PUSHER - Ch %d Get 0x%02x%08x "
+                                            "Put 0x%02x%08x IbGet 0x%08x IbPut 0x%08x "
+                                            "State 0x%08x Push 0x%08x\n",
+                                       chid, ho_get, get, ho_put, put, ib_get, ib_put,
+                                       state, push);
+
+                               /* METHOD_COUNT, in DMA_STATE on earlier chipsets */
+                               nv_wr32(dev, 0x003364, 0x00000000);
+                               if (get != put || ho_get != ho_put) {
+                                       nv_wr32(dev, 0x003244, put);
+                                       nv_wr32(dev, 0x003328, ho_put);
+                               } else
+                               if (ib_get != ib_put) {
+                                       nv_wr32(dev, 0x003334, ib_put);
+                               }
+                       } else {
+                               NV_INFO(dev, "PFIFO_DMA_PUSHER - Ch %d Get 0x%08x "
+                                            "Put 0x%08x State 0x%08x Push 0x%08x\n",
+                                       chid, get, put, state, push);
 
-                       status &= ~NV_PFIFO_INTR_DMA_PUSHER;
-                       nv_wr32(dev, NV03_PFIFO_INTR_0,
-                                               NV_PFIFO_INTR_DMA_PUSHER);
+                               if (get != put)
+                                       nv_wr32(dev, 0x003244, put);
+                       }
 
-                       nv_wr32(dev, NV04_PFIFO_CACHE1_DMA_STATE, 0x00000000);
-                       if (nv_rd32(dev, NV04_PFIFO_CACHE1_DMA_PUT) != get)
-                               nv_wr32(dev, NV04_PFIFO_CACHE1_DMA_GET,
-                                                               get + 4);
+                       nv_wr32(dev, 0x003228, 0x00000000);
+                       nv_wr32(dev, 0x003220, 0x00000001);
+                       nv_wr32(dev, 0x002100, NV_PFIFO_INTR_DMA_PUSHER);
+                       status &= ~NV_PFIFO_INTR_DMA_PUSHER;
                }
 
                if (status & NV_PFIFO_INTR_SEMAPHORE) {