diff --git a/drivers/scsi/gdth.c b/drivers/scsi/gdth.c
index bd3ffdf6c800088d5e6de6b915a6727eaa912757..62e3cda859afccb44dda94dc9c2a6d2ab0a18d31 100644
--- a/drivers/scsi/gdth.c
+++ b/drivers/scsi/gdth.c
@@ -2816,7 +2816,7 @@ static int gdth_fill_cache_cmd(int hanum,Scsi_Cmnd *scp,ushort hdrive)
             }
 #endif
 
-        } else {
+        } else if (scp->request_bufflen) {
             scp->SCp.Status = GDTH_MAP_SINGLE;
             scp->SCp.Message = (read_write == 1 ? 
                 PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);