1 files changed, 20 insertions, 12 deletions

diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index 79a3203eccd9..be416d6850f0 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -507,17 +507,37 @@ static void ntb_transport_setup_qp_mw(struct ntb_transport *nt,
         qp->tx_pkts = 0;
 }
 
+static void ntb_free_mw(struct ntb_transport *nt, int num_mw)
+{
+        struct ntb_transport_mw *mw = &nt->mw[num_mw];
+        struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
+
+        if (!mw->virt_addr)
+                return;
+
+        dma_free_coherent(&pdev->dev, mw->size, mw->virt_addr, mw->dma_addr);
+        mw->virt_addr = NULL;
+}
+
 static int ntb_set_mw(struct ntb_transport *nt, int num_mw, unsigned int size)
 {
         struct ntb_transport_mw *mw = &nt->mw[num_mw];
         struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
 
+        /* No need to re-setup */
+        if (mw->size == ALIGN(size, 4096))
+                return 0;
+
+        if (mw->size != 0)
+                ntb_free_mw(nt, num_mw);
+
         /* Alloc memory for receiving data.  Must be 4k aligned */
         mw->size = ALIGN(size, 4096);
 
         mw->virt_addr = dma_alloc_coherent(&pdev->dev, mw->size, &mw->dma_addr,
                                            GFP_KERNEL);
         if (!mw->virt_addr) {
+                mw->size = 0;
                 dev_err(&pdev->dev, "Unable to allocate MW buffer of size %d\n",
                        (int) mw->size);
                 return -ENOMEM;
@@ -529,18 +549,6 @@ static int ntb_set_mw(struct ntb_transport *nt, int num_mw, unsigned int size)
         return 0;
 }
 
-static void ntb_free_mw(struct ntb_transport *nt, int num_mw)
-{
-        struct ntb_transport_mw *mw = &nt->mw[num_mw];
-        struct pci_dev *pdev = ntb_query_pdev(nt->ndev);
-
-        if (!mw->virt_addr)
-                return;
-
-        dma_free_coherent(&pdev->dev, mw->size, mw->virt_addr, mw->dma_addr);
-        mw->virt_addr = NULL;
-}
-
 static void ntb_qp_link_cleanup(struct work_struct *work)
 {
         struct ntb_transport_qp *qp = container_of(work,