Hello Hannes Reinecke,
The patch 8a8606895947: "scsi: myrs: Add Mylex RAID controller (SCSI
interface)" from Jan 24, 2018, leads to the following static checker
warning:
drivers/scsi/myrs.c:479 myrs_get_event()
warn: right shifting more than type allows 16 vs 16
drivers/scsi/myrs.c
461 static unsigned char
462 myrs_get_event(myrs_hba *cs, unsigned short event_num,
^^^^^^^^^^^^^^^^^^^^^^^^
463 myrs_event *event_buf)
464 {
465 struct pci_dev *pdev = cs->pdev;
466 dma_addr_t event_addr;
467 myrs_cmdblk *cmd_blk = &cs->mcmd_blk;
468 myrs_cmd_mbox *mbox = &cmd_blk->mbox;
469 myrs_sgl *sgl;
470 unsigned char status;
471
472 event_addr = dma_map_single(&pdev->dev, event_buf,
473 sizeof(myrs_event),
DMA_FROM_DEVICE);
474 if (dma_mapping_error(&pdev->dev, event_addr))
475 return DAC960_V2_AbnormalCompletion;
476
477 mbox->GetEvent.opcode = DAC960_V2_IOCTL;
478 mbox->GetEvent.dma_size = sizeof(myrs_event);
479 mbox->GetEvent.evnum_upper = event_num >> 16;
^^^^^^^^^^^^^^^
This is always going to be zero.
480 mbox->GetEvent.ctlr_num = 0;
481 mbox->GetEvent.ioctl_opcode = DAC960_V2_GetEvent;
482 mbox->GetEvent.evnum_lower = event_num & 0xFFFF;
483 sgl = &mbox->GetEvent.dma_addr;
484 sgl->sge[0].sge_addr = event_addr;
485 sgl->sge[0].sge_count = mbox->GetEvent.dma_size;
486 myrs_exec_cmd(cs, cmd_blk);
487 status = cmd_blk->status;
488 dma_unmap_single(&pdev->dev, event_addr,
489 sizeof(myrs_event), DMA_FROM_DEVICE);
490
491 return status;
492 }
This warning is probably a false positive which you can ignore but what
made me question it was looking at the caller:
drivers/scsi/myrs.c
2222 static void myrs_monitor(struct work_struct *work)
2223 {
2224 myrs_hba *cs = container_of(work, myrs_hba, monitor_work.work);
2225 struct Scsi_Host *shost = cs->host;
2226 myrs_ctlr_info *info = cs->ctlr_info;
2227 unsigned int epoch = cs->fwstat_buf->epoch;
2228 unsigned long interval = MYRS_PRIMARY_MONITOR_INTERVAL;
2229 unsigned char status;
2230
2231 dev_dbg(&shost->shost_gendev, "monitor tick\n");
2232
2233 status = myrs_get_fwstatus(cs);
2234
2235 if (cs->needs_update) {
2236 cs->needs_update = false;
2237 mutex_lock(&cs->cinfo_mutex);
2238 status = myrs_get_ctlr_info(cs);
2239 mutex_unlock(&cs->cinfo_mutex);
2240 }
2241 if (cs->fwstat_buf->next_evseq - cs->next_evseq > 0) {
2242 status = myrs_get_event(cs, cs->next_evseq,
^^^^^^^^^^^^^^
This is an int.
2243 cs->event_buf);
2244 if (status == DAC960_V2_NormalCompletion) {
2245 myrs_log_event(cs, cs->event_buf);
2246 cs->next_evseq++;
^^^^^^^^^^^^^^^^
And I guess this is where we set cs->next_evseq.
2247 interval = 1;
2248 }
2249 }
regards,
dan carpenter
