[SCSI] aic79xx: 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, 5 insertions, 2 deletions

diff --git a/drivers/scsi/aic7xxx/aic79xx_osm.c b/drivers/scsi/aic7xxx/aic79xx_osm.c
index 72fccd9f40df..0081aa357c8b 100644
--- a/drivers/scsi/aic7xxx/aic79xx_osm.c
+++ b/drivers/scsi/aic7xxx/aic79xx_osm.c
@@ -1413,6 +1413,10 @@ ahd_linux_run_command(struct ahd_softc *ahd, struct ahd_linux_device *dev,
         unsigned long flags;
         int nseg;
 
+        nseg = scsi_dma_map(cmd);
+        if (nseg < 0)
+                return SCSI_MLQUEUE_HOST_BUSY;
+
         ahd_lock(ahd, &flags);
 
         /*
@@ -1430,6 +1434,7 @@ ahd_linux_run_command(struct ahd_softc *ahd, struct ahd_linux_device *dev,
         if ((scb = ahd_get_scb(ahd, col_idx)) == NULL) {
                 ahd->flags |= AHD_RESOURCE_SHORTAGE;
                 ahd_unlock(ahd, &flags);
+                scsi_dma_unmap(cmd);
                 return SCSI_MLQUEUE_HOST_BUSY;
         }
 
@@ -1485,8 +1490,6 @@ ahd_linux_run_command(struct ahd_softc *ahd, struct ahd_linux_device *dev,
         ahd_set_sense_residual(scb, 0);
         scb->sg_count = 0;
 
-        nseg = scsi_dma_map(cmd);
-        BUG_ON(nseg < 0);
         if (nseg > 0) {
                 void *sg = scb->sg_list;
                 struct scatterlist *cur_seg;