1 files changed, 22 insertions, 2 deletions

diff --git a/drivers/dma/ioat/dma_v2.c b/drivers/dma/ioat/dma_v2.c
index 3c8b32a83794..216f9d383b5b 100644
--- a/drivers/dma/ioat/dma_v2.c
+++ b/drivers/dma/ioat/dma_v2.c
@@ -287,7 +287,10 @@ void ioat2_timer_event(unsigned long data)
                         chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
                         dev_err(to_dev(chan), "%s: Channel halted (%x)\n",
                                 __func__, chanerr);
-                        BUG_ON(is_ioat_bug(chanerr));
+                        if (test_bit(IOAT_RUN, &chan->state))
+                                BUG_ON(is_ioat_bug(chanerr));
+                        else /* we never got off the ground */
+                                return;
                 }
 
                 /* if we haven't made progress and we have already
@@ -492,6 +495,8 @@ static struct ioat_ring_ent **ioat2_alloc_ring(struct dma_chan *c, int order, gf
         return ring;
 }
 
+void ioat2_free_chan_resources(struct dma_chan *c);
+
 /* ioat2_alloc_chan_resources - allocate/initialize ioat2 descriptor ring
  * @chan: channel to be initialized
  */
@@ -500,6 +505,7 @@ int ioat2_alloc_chan_resources(struct dma_chan *c)
         struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
         struct ioat_chan_common *chan = &ioat->base;
         struct ioat_ring_ent **ring;
+        u64 status;
         int order;
 
         /* have we already been set up? */
@@ -540,7 +546,20 @@ int ioat2_alloc_chan_resources(struct dma_chan *c)
         tasklet_enable(&chan->cleanup_task);
         ioat2_start_null_desc(ioat);
 
-        return 1 << ioat->alloc_order;
+        /* check that we got off the ground */
+        udelay(5);
+        status = ioat_chansts(chan);
+        if (is_ioat_active(status) || is_ioat_idle(status)) {
+                set_bit(IOAT_RUN, &chan->state);
+                return 1 << ioat->alloc_order;
+        } else {
+                u32 chanerr = readl(chan->reg_base + IOAT_CHANERR_OFFSET);
+
+                dev_WARN(to_dev(chan),
+                        "failed to start channel chanerr: %#x\n", chanerr);
+                ioat2_free_chan_resources(c);
+                return -EFAULT;
+        }
 }
 
 bool reshape_ring(struct ioat2_dma_chan *ioat, int order)
@@ -778,6 +797,7 @@ void ioat2_free_chan_resources(struct dma_chan *c)
         del_timer_sync(&chan->timer);
         device->cleanup_fn((unsigned long) c);
         device->reset_hw(chan);
+        clear_bit(IOAT_RUN, &chan->state);
 
         spin_lock_bh(&chan->cleanup_lock);
         spin_lock_bh(&ioat->prep_lock);