mpt3sas: Return host busy error status to SML when DMA mapping of scatter gather...

scsi_dma_map API will return a negative value (i.e. -ENOMEM)
if DMA mapping of sg lists fails and zero if the sg list in the
SCSI cmd is NULL. But drivers doesn't handled sg list DMA mapping
failure case properly.

So, Updated the code to return host busy error status to SCSI MID Layer(SML),
when DMA mapping of scatter gather list fails for a SCSI command.
So that SML will retry this SCSI cmd after some time.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 3c8561cb6d8460cc26a197948340307f9bb92ff0..d4d4e6c0b956758aa6b24ebcb3c014fddd8dfe6b 100644 (file)
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -1360,7 +1360,7 @@ _base_build_sg_scmd_ieee(struct MPT3SAS_ADAPTER *ioc,
 
        sg_scmd = scsi_sglist(scmd);
        sges_left = scsi_dma_map(scmd);
-       if (!sges_left) {
+       if (sges_left < 0) {
                sdev_printk(KERN_ERR, scmd->device,
                        "pci_map_sg failed: request for %d bytes!\n",
                        scsi_bufflen(scmd));
@@ -1429,7 +1429,7 @@ _base_build_sg_scmd_ieee(struct MPT3SAS_ADAPTER *ioc,
  fill_in_last_segment:
 
        /* fill the last segment */
-       while (sges_left) {
+       while (sges_left > 0) {
                if (sges_left == 1)
                        _base_add_sg_single_ieee(sg_local,
                            simple_sgl_flags_last, 0, sg_dma_len(sg_scmd),