linux/drivers/scsi/mvsas
Dan Williams b1124cd3ec [SCSI] libsas: introduce sas_drain_work()
When an lldd invokes ->notify_port_event() it can trigger a chain of libsas
events to:

  1/ form the port and find the direct attached device

  2/ if the attached device is an expander perform domain discovery

A call to flush_workqueue() will only flush the initial port formation work.
Currently libsas users need to call scsi_flush_work() up to the max depth of
chain (which will grow from 2 to 3 when ata discovery is moved to its own
discovery event).  Instead of open coding multiple calls switch to use
drain_workqueue() to flush sas work.

drain_workqueue() does not handle new work submitted during the drain so
libsas needs a bit of infrastructure to hold off unchained work submissions
while a drain is in flight.  A lldd ->notify() event is considered 'unchained'
while a sas_discover_event() is 'chained'.  As Tejun notes:

  "For now, I think it would be best to add private wrapper in libsas to
   support deferring unchained work items while draining."

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-02-19 13:48:51 -06:00
..
Kconfig [SCSI] mvsas: Add support for interrupt tasklet 2011-07-26 12:59:55 +04:00
Makefile [SCSI] mvsas: add support for Task collector mode and fixed relative bugs 2011-05-01 12:08:03 -05:00
mv_64xx.c [SCSI] mvsas: Add support for interrupt tasklet 2011-07-26 12:59:55 +04:00
mv_64xx.h [SCSI] mvsas: add support for Task collector mode and fixed relative bugs 2011-05-01 12:08:03 -05:00
mv_94xx.c [SCSI] mvsas: fixed SMP request watchdog timeout issue. 2011-10-02 13:18:01 -05:00
mv_94xx.h [SCSI] mvsas: update comments 2011-07-26 10:39:09 +04:00
mv_chips.h [SCSI] mvsas: update comments 2011-07-26 10:39:09 +04:00
mv_defs.h [SCSI] mvsas: fixed SMP request watchdog timeout issue. 2011-10-02 13:18:01 -05:00
mv_init.c [SCSI] libsas: kill sas_slave_destroy 2012-02-19 13:36:36 -06:00
mv_sas.c [SCSI] libsas: introduce sas_drain_work() 2012-02-19 13:48:51 -06:00
mv_sas.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6 2011-10-28 16:44:18 -07:00