[bug report] i3c: master: svc: Add Silvaco I3C master driver

[Dan Carpenter]

Hello Miquel Raynal,

The patch dd3c52846d59: "i3c: master: svc: Add Silvaco I3C master
driver" from Jan 21, 2021, leads to the following static checker
warning:

	drivers/i3c/master/svc-i3c-master.c:394 svc_i3c_master_ibi_work()
	error: uninitialized symbol 'dev'.

drivers/i3c/master/svc-i3c-master.c
   364          status = readl(master->regs + SVC_I3C_MSTATUS);
   365          ibitype = SVC_I3C_MSTATUS_IBITYPE(status);
   366          ibiaddr = SVC_I3C_MSTATUS_IBIADDR(status);
   367  
   368          /* Handle the critical responses to IBI's */
   369          switch (ibitype) {
   370          case SVC_I3C_MSTATUS_IBITYPE_IBI:
   371                  dev = svc_i3c_master_dev_from_addr(master, ibiaddr);
   372                  if (!dev)
   373                          svc_i3c_master_nack_ibi(master);
   374                  else
   375                          svc_i3c_master_handle_ibi(master, dev);

"dev" only valid on this path.

   376                  break;
   377          case SVC_I3C_MSTATUS_IBITYPE_HOT_JOIN:
   378                  svc_i3c_master_ack_ibi(master, false);
   379                  break;
   380          case SVC_I3C_MSTATUS_IBITYPE_MASTER_REQUEST:
   381                  svc_i3c_master_nack_ibi(master);
   382                  break;
   383          default:
   384                  break;
   385          }
   386  
   387          /*
   388           * If an error happened, we probably got interrupted and the exchange
   389           * timedout. In this case we just drop everything, emit a stop and wait
   390           * for the slave to interrupt again.
   391           */
   392          if (svc_i3c_master_error(master)) {
   393                  if (master->ibi.tbq_slot) {
   394                          data = i3c_dev_get_master_data(dev);
                                                               ^^^
Dereferenced here.

   395                          i3c_generic_ibi_recycle_slot(data->ibi_pool,
   396                                                       master->ibi.tbq_slot);
   397                          master->ibi.tbq_slot = NULL;
   398                  }
   399  
   400                  svc_i3c_master_emit_stop(master);
   401  
   402                  goto reenable_ibis;
   403          }
   404  
   405          /* Handle the non critical tasks */

regards,
dan carpenter