[SCSI] qla2xxx: Free DMA memory only if it is allocated in vendor specific BSG command

The qla84xx_mgmt_cmd function supports multiple subcommands.
Some subcommands require DMA memory and some do not.
Therefore check before freeing DMA memory whether it is allocated or not.

Signed-off-by: Harish Zunjarrao <harish.zunjarrao@qlogic.com>
Signed-off-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/scsi/qla2xxx/qla_bsg.c b/drivers/scsi/qla2xxx/qla_bsg.c
index 3c3a86ca6cbd..584c52d134fa 100644
--- a/drivers/scsi/qla2xxx/qla_bsg.c
+++ b/drivers/scsi/qla2xxx/qla_bsg.c
@@ -804,7 +804,7 @@ qla84xx_mgmt_cmd(struct fc_bsg_job *bsg_job)
         int rval = 0;
         struct qla_bsg_a84_mgmt *ql84_mgmt;
         uint32_t sg_cnt;
-        uint32_t data_len;
+        uint32_t data_len = 0;
         uint32_t dma_direction = DMA_NONE;
 
         if (test_bit(ISP_ABORT_NEEDED, &vha->dpc_flags) ||
@@ -980,9 +980,11 @@ qla84xx_mgmt_cmd(struct fc_bsg_job *bsg_job)
         }
 
         bsg_job->job_done(bsg_job);
-        dma_free_coherent(&ha->pdev->dev, data_len, mgmt_b, mgmt_dma);
 
 done_unmap_sg:
+        if (mgmt_b)
+                dma_free_coherent(&ha->pdev->dev, data_len, mgmt_b, mgmt_dma);
+
         if (dma_direction == DMA_TO_DEVICE)
                 dma_unmap_sg(&ha->pdev->dev, bsg_job->request_payload.sg_list,
                         bsg_job->request_payload.sg_cnt, DMA_TO_DEVICE);