[SCSI] fix panic when ejecting ieee1394 ipod

The scsi_library routines don't correctly set DMA_NONE when
req->data_len is zero (instead they check the command type first, so
if it's write, we end up with req->data_len == 0 and direction as
DMA_TO_DEVICE which confuses some drivers)

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 4afef5cdcb17568c1380d3987d1e4c4661dc16e4..097888721ec43af6a80a9cf71e860ed86ac86d89 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1215,12 +1215,12 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
                } else {
                        memcpy(cmd->cmnd, req->cmd, sizeof(cmd->cmnd));
                        cmd->cmd_len = req->cmd_len;
-                       if (rq_data_dir(req) == WRITE)
+                       if (!req->data_len)
+                               cmd->sc_data_direction = DMA_NONE;
+                       else if (rq_data_dir(req) == WRITE)
                                cmd->sc_data_direction = DMA_TO_DEVICE;
-                       else if (req->data_len)
-                               cmd->sc_data_direction = DMA_FROM_DEVICE;
                        else
-                               cmd->sc_data_direction = DMA_NONE;
+                               cmd->sc_data_direction = DMA_FROM_DEVICE;
                        
                        cmd->transfersize = req->data_len;
                        cmd->allowed = 3;