pm8001: locking in mpi_sata_completion() is broken

[Dan Carpenter <dan.carpenter@oracle.com>]

The locking in mpi_sata_completion() is broken.  I'm not sure what was
intended at all.  Here is what it does:

  1876  mpi_sata_completion(struct pm8001_hba_info *pm8001_ha, void *piomb)
  1877  {
  1878          struct sas_task *t;
  1879          struct pm8001_ccb_info *ccb;
  1880          unsigned long flags = 0;
                ^^^^^^^^^^^^^^^^^^^^^^^
This is bogus.  The flags should be set with irqsave.  This implies a
knowledge of the internals which should be abstracted away.

	[snip]

  2006          case IO_OPEN_CNX_ERROR_IT_NEXUS_LOSS:
  2007                  PM8001_IO_DBG(pm8001_ha,
  2008                          pm8001_printk("IO_OPEN_CNX_ERROR_IT_NEXUS_LOSS\n"));
  2009                  ts->resp = SAS_TASK_COMPLETE;
  2010                  ts->stat = SAS_DEV_NO_RESPONSE;
  2011                  if (!t->uldd_task) {
  2012                          pm8001_handle_event(pm8001_ha,
  2013                                  pm8001_dev,
  2014                                  IO_OPEN_CNX_ERROR_IT_NEXUS_LOSS);
  2015                          ts->resp = SAS_TASK_UNDELIVERED;
  2016                          ts->stat = SAS_QUEUE_FULL;
  2017                          pm8001_ccb_task_free(pm8001_ha, t, ccb, tag);
  2018                          mb();/*in order to force CPU ordering*/
  2019                          spin_unlock_irqrestore(&pm8001_ha->lock, flags);
                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Calling irqrestore before we've done an irqsave.  What are we trying to
restore?

  2020                          t->task_done(t);
  2021                          spin_lock_irqsave(&pm8001_ha->lock, flags);
  2022                          return;
  2023                  }

	[snip]

  2197                  spin_unlock_irqrestore(&t->task_state_lock, flags);
  2198                  pm8001_ccb_task_free(pm8001_ha, t, ccb, tag);
  2199                  mb();/*ditto*/
  2200                  spin_unlock_irqrestore(&pm8001_ha->lock, flags);
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
We just called irqrestore so there is no need to restore it twice.

  2201                  t->task_done(t);
  2202                  spin_lock_irqsave(&pm8001_ha->lock, flags);
                                                            ^^^^^
We're saving the irq status but we're at the end of the function so we
never use it again.

  2203          }
  2204  }

I've just picked out a couple examples, but basically the whole function
is like that.

regards,
dan carpenter