drm/nvc0: improve vm flush function

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

diff --git a/drivers/gpu/drm/nouveau/nvc0_vm.c b/drivers/gpu/drm/nouveau/nvc0_vm.c
index 69af0ba..a0a2a02 100644 (file)
--- a/drivers/gpu/drm/nouveau/nvc0_vm.c
+++ b/drivers/gpu/drm/nouveau/nvc0_vm.c
@@ -104,20 +104,26 @@ nvc0_vm_flush(struct nouveau_vm *vm)
        struct nouveau_instmem_engine *pinstmem = &dev_priv->engine.instmem;
        struct drm_device *dev = vm->dev;
        struct nouveau_vm_pgd *vpgd;
-       u32 r100c80, engine;
+       u32 engine = (dev_priv->chan_vm == vm) ? 1 : 5;
 
        pinstmem->flush(vm->dev);
 
-       if (vm == dev_priv->chan_vm)
-               engine = 1;
-       else
-               engine = 5;
-
+       spin_lock(&dev_priv->ramin_lock);
        list_for_each_entry(vpgd, &vm->pgd_list, head) {
-               r100c80 = nv_rd32(dev, 0x100c80);
+               /* looks like maybe a "free flush slots" counter, the
+                * faster you write to 0x100cbc to more it decreases
+                */
+               if (!nv_wait_ne(dev, 0x100c80, 0x00ff0000, 0x00000000)) {
+                       NV_ERROR(dev, "vm timeout 0: 0x%08x %d\n",
+                                nv_rd32(dev, 0x100c80), engine);
+               }
                nv_wr32(dev, 0x100cb8, vpgd->obj->vinst >> 8);
                nv_wr32(dev, 0x100cbc, 0x80000000 | engine);
-               if (!nv_wait(dev, 0x100c80, 0xffffffff, r100c80))
-                       NV_ERROR(dev, "vm flush timeout eng %d\n", engine);
+               /* wait for flush to be queued? */
+               if (!nv_wait(dev, 0x100c80, 0x00008000, 0x00008000)) {
+                       NV_ERROR(dev, "vm timeout 1: 0x%08x %d\n",
+                                nv_rd32(dev, 0x100c80), engine);
+               }
        }
+       spin_unlock(&dev_priv->ramin_lock);
 }