drm/nvc0: improve vm flush function

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

1 files changed, 15 insertions, 9 deletions

diff --git a/drivers/gpu/drm/nouveau/nvc0_vm.c b/drivers/gpu/drm/nouveau/nvc0_vm.c
index 69af0ba7edd3..a0a2a0277f73 100644
--- 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);
 }