IB/hfi1: Preserve external device completed bit

The driver should not change the external device request
completed bit when not actually doing an external device
request.

Reviewed-by: Easwar Hariharan <easwar.hariharan@intel.com>
Signed-off-by: Dean Luick <dean.luick@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/hfi1/chip.c

@@ -8488,7 +8488,10 @@ static int do_8051_command(
 	 */
 	if (type == HCMD_WRITE_LCB_CSR) {
 		in_data |= ((*out_data) & 0xffffffffffull) << 8;
-		reg = ((((*out_data) >> 40) & 0xff) <<
+		/* must preserve COMPLETED - it is tied to hardware */
+		reg = read_csr(dd, DC_DC8051_CFG_EXT_DEV_0);
+		reg &= DC_DC8051_CFG_EXT_DEV_0_COMPLETED_SMASK;
+		reg |= ((((*out_data) >> 40) & 0xff) <<
 				DC_DC8051_CFG_EXT_DEV_0_RETURN_CODE_SHIFT)
 		      | ((((*out_data) >> 48) & 0xffff) <<
 				DC_DC8051_CFG_EXT_DEV_0_RSP_DATA_SHIFT);