drm/nouveau/fifo/g84-: ack non-stall interrupt before handling it

Closes a very unlikely race that can occur if another NonStallInterrupt
method passes between checking fences and acking the previous interrupt.

With this change, the interrupt will re-fire under such conditions.

Tested-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

3 files changed, 4 insertions, 4 deletions

diff --git a/drivers/gpu/drm/nouveau/core/engine/fifo/nv04.c b/drivers/gpu/drm/nouveau/core/engine/fifo/nv04.c
index 5ae6a43893b5..1931057f9962 100644
--- a/drivers/gpu/drm/nouveau/core/engine/fifo/nv04.c
+++ b/drivers/gpu/drm/nouveau/core/engine/fifo/nv04.c
@@ -551,8 +551,8 @@ nv04_fifo_intr(struct nouveau_subdev *subdev)
                         }
 
                         if (status & 0x40000000) {
-                                nouveau_fifo_uevent(&priv->base);
                                 nv_wr32(priv, 0x002100, 0x40000000);
+                                nouveau_fifo_uevent(&priv->base);
                                 status &= ~0x40000000;
                         }
                 }
diff --git a/drivers/gpu/drm/nouveau/core/engine/fifo/nvc0.c b/drivers/gpu/drm/nouveau/core/engine/fifo/nvc0.c
index 1fe1f8fbda0c..074d434c3077 100644
--- a/drivers/gpu/drm/nouveau/core/engine/fifo/nvc0.c
+++ b/drivers/gpu/drm/nouveau/core/engine/fifo/nvc0.c
@@ -740,6 +740,8 @@ nvc0_fifo_intr_engine_unit(struct nvc0_fifo_priv *priv, int engn)
         u32 inte = nv_rd32(priv, 0x002628);
         u32 unkn;
 
+        nv_wr32(priv, 0x0025a8 + (engn * 0x04), intr);
+
         for (unkn = 0; unkn < 8; unkn++) {
                 u32 ints = (intr >> (unkn * 0x04)) & inte;
                 if (ints & 0x1) {
@@ -751,8 +753,6 @@ nvc0_fifo_intr_engine_unit(struct nvc0_fifo_priv *priv, int engn)
                         nv_mask(priv, 0x002628, ints, 0);
                 }
         }
-
-        nv_wr32(priv, 0x0025a8 + (engn * 0x04), intr);
 }
 
 static void
diff --git a/drivers/gpu/drm/nouveau/core/engine/fifo/nve0.c b/drivers/gpu/drm/nouveau/core/engine/fifo/nve0.c
index d2f0fd39c145..f8734eb74eaa 100644
--- a/drivers/gpu/drm/nouveau/core/engine/fifo/nve0.c
+++ b/drivers/gpu/drm/nouveau/core/engine/fifo/nve0.c
@@ -952,8 +952,8 @@ nve0_fifo_intr(struct nouveau_subdev *subdev)
         }
 
         if (stat & 0x80000000) {
-                nve0_fifo_intr_engine(priv);
                 nv_wr32(priv, 0x002100, 0x80000000);
+                nve0_fifo_intr_engine(priv);
                 stat &= ~0x80000000;
         }