[PATCH 4/4] Don't crash on IOMMU overflow in A100U2W driver

Mikulas Patocka
2008-07-15T21:20:47Z

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

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
---
drivers/scsi/a100u2w.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

Index: linux-2.6.26-fast/drivers/scsi/a100u2w.c
===================================================================
--- linux-2.6.26-fast.orig/drivers/scsi/a100u2w.c 2008-07-15 15:49:39.000000000 +0200
+++ linux-2.6.26-fast/drivers/scsi/a100u2w.c 2008-07-15 16:04:50.000000000 +0200
@@ -840,7 +840,7 @@ static irqreturn_t orc_interrupt(struct
* 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
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
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_cmn
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;
}