[SCSI] aic7xxx: fix IOMMU mapping failure handling

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/drivers/scsi/aic7xxx/aic7xxx_osm.c b/drivers/scsi/aic7xxx/aic7xxx_osm.c
index 282aff6f852e..42ad48e09f02 100644
--- a/drivers/scsi/aic7xxx/aic7xxx_osm.c
+++ b/drivers/scsi/aic7xxx/aic7xxx_osm.c
@@ -1398,12 +1398,18 @@ ahc_linux_run_command(struct ahc_softc *ahc, struct ahc_linux_device *dev,
                         return SCSI_MLQUEUE_DEVICE_BUSY;
         }
 
+        nseg = scsi_dma_map(cmd);
+        if (nseg < 0)
+                return SCSI_MLQUEUE_HOST_BUSY;
+
         /*
          * Get an scb to use.
          */
         scb = ahc_get_scb(ahc);
-        if (!scb)
+        if (!scb) {
+                scsi_dma_unmap(cmd);
                 return SCSI_MLQUEUE_HOST_BUSY;
+        }
 
         scb->io_ctx = cmd;
         scb->platform_data->dev = dev;
@@ -1464,8 +1470,6 @@ ahc_linux_run_command(struct ahc_softc *ahc, struct ahc_linux_device *dev,
         ahc_set_sense_residual(scb, 0);
         scb->sg_count = 0;
 
-        nseg = scsi_dma_map(cmd);
-        BUG_ON(nseg < 0);
         if (nseg > 0) {
                 struct  ahc_dma_seg *sg;
                 struct  scatterlist *cur_seg;