1 files changed, 8 insertions, 7 deletions

diff --git a/drivers/parisc/iommu-helpers.h b/drivers/parisc/iommu-helpers.h
index 761e77bfce5d..e56f1569f6c3 100644
--- a/drivers/parisc/iommu-helpers.h
+++ b/drivers/parisc/iommu-helpers.h
@@ -104,7 +104,11 @@ iommu_coalesce_chunks(struct ioc *ioc, struct device *dev,
         struct scatterlist *contig_sg;     /* contig chunk head */
         unsigned long dma_offset, dma_len; /* start/len of DMA stream */
         unsigned int n_mappings = 0;
-        unsigned int max_seg_size = dma_get_max_seg_size(dev);
+        unsigned int max_seg_size = min(dma_get_max_seg_size(dev),
+                                        (unsigned)DMA_CHUNK_SIZE);
+        unsigned int max_seg_boundary = dma_get_seg_boundary(dev) + 1;
+        if (max_seg_boundary)   /* check if the addition above didn't overflow */
+                max_seg_size = min(max_seg_size, max_seg_boundary);
 
         while (nents > 0) {
 
@@ -138,14 +142,11 @@ iommu_coalesce_chunks(struct ioc *ioc, struct device *dev,
 
                         /*
                         ** First make sure current dma stream won't
-                        ** exceed DMA_CHUNK_SIZE if we coalesce the
+                        ** exceed max_seg_size if we coalesce the
                         ** next entry.
                         */   
-                        if(unlikely(ALIGN(dma_len + dma_offset + startsg->length,
-                                            IOVP_SIZE) > DMA_CHUNK_SIZE))
-                                break;
-
-                        if (startsg->length + dma_len > max_seg_size)
+                        if (unlikely(ALIGN(dma_len + dma_offset + startsg->length, IOVP_SIZE) >
+                                     max_seg_size))
                                 break;
 
                         /*