Don't crash on IOMMU overflow in A100U2W driver

Handle IOMMU overflow correctly, by retrying.  IOMMU errors can happen
and drivers must deal with them.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 3 deletions

diff --git a/drivers/scsi/a100u2w.c b/drivers/scsi/a100u2w.c
index f5051f4301d7..84bb61628372 100644
--- a/drivers/scsi/a100u2w.c
+++ b/drivers/scsi/a100u2w.c
@@ -840,7 +840,7 @@ static irqreturn_t orc_interrupt(struct orc_host * host)
  *      Build a host adapter control block from the SCSI mid layer command
  */
 
-static void inia100_build_scb(struct orc_host * host, struct orc_scb * scb, struct scsi_cmnd * cmd)
+static int inia100_build_scb(struct orc_host * host, struct orc_scb * scb, struct scsi_cmnd * cmd)
 {                               /* Create corresponding SCB     */
         struct scatterlist *sg;
         struct orc_sgent *sgent;                /* Pointer to SG list           */
@@ -865,7 +865,8 @@ static void inia100_build_scb(struct orc_host * host, struct orc_scb * scb, stru
         sgent = (struct orc_sgent *) & escb->sglist[0];
 
         count_sg = scsi_dma_map(cmd);
-        BUG_ON(count_sg < 0);
+        if (count_sg < 0)
+                return count_sg;
         BUG_ON(count_sg > TOTAL_SG_ENTRY);
 
         /* Build the scatter gather lists */
@@ -898,6 +899,7 @@ static void inia100_build_scb(struct orc_host * host, struct orc_scb * scb, stru
                 scb->tag_msg = 0;       /* No tag support               */
         }
         memcpy(scb->cdb, cmd->cmnd, scb->cdb_len);
+        return 0;
 }
 
 /**
@@ -921,7 +923,10 @@ static int inia100_queue(struct scsi_cmnd * cmd, void (*done) (struct scsi_cmnd
         if ((scb = orc_alloc_scb(host)) == NULL)
                 return SCSI_MLQUEUE_HOST_BUSY;
 
-        inia100_build_scb(host, scb, cmd);
+        if (inia100_build_scb(host, scb, cmd)) {
+                orc_release_scb(host, scb);
+                return SCSI_MLQUEUE_HOST_BUSY;
+        }
         orc_exec_scb(host, scb);        /* Start execute SCB            */
         return 0;
 }