1 files changed, 7 insertions, 3 deletions

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index c38083871f11..2defd1308b04 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -463,7 +463,7 @@ static int active_pfn_set_overlap(unsigned long pfn, int overlap)
         int i;
 
         if (overlap > ACTIVE_PFN_MAX_OVERLAP || overlap < 0)
-                return 0;
+                return overlap;
 
         for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
                 if (overlap & 1 << i)
@@ -486,7 +486,7 @@ static void active_pfn_inc_overlap(unsigned long pfn)
          * debug_dma_assert_idle() as the pfn may be marked idle
          * prematurely.
          */
-        WARN_ONCE(overlap == 0,
+        WARN_ONCE(overlap > ACTIVE_PFN_MAX_OVERLAP,
                   "DMA-API: exceeded %d overlapping mappings of pfn %lx\n",
                   ACTIVE_PFN_MAX_OVERLAP, pfn);
 }
@@ -517,7 +517,11 @@ static void active_pfn_remove(struct dma_debug_entry *entry)
         unsigned long flags;
 
         spin_lock_irqsave(&radix_lock, flags);
-        if (active_pfn_dec_overlap(entry->pfn) == 0)
+        /* since we are counting overlaps the final put of the
+         * entry->pfn will occur when the overlap count is 0.
+         * active_pfn_dec_overlap() returns -1 in that case
+         */
+        if (active_pfn_dec_overlap(entry->pfn) < 0)
                 radix_tree_delete(&dma_active_pfn, entry->pfn);
         spin_unlock_irqrestore(&radix_lock, flags);
 }