diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2011-12-19 16:42:34 -0800 |
|---|---|---|
| committer | James Bottomley <JBottomley@Parallels.com> | 2012-02-19 13:48:51 -0600 |
| commit | b1124cd3ec97406c767b90bf7e93ecd2d2915592 (patch) | |
| tree | d0936775aacff4492177c14a73175738dfb51ee0 /drivers/scsi/isci/host.c | |
| parent | f8daa6e6d83f60a721752cb53433bfdc1503b45f (diff) | |
[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>
Diffstat (limited to 'drivers/scsi/isci/host.c')
| -rw-r--r-- | drivers/scsi/isci/host.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/drivers/scsi/isci/host.c b/drivers/scsi/isci/host.c index 508aa8ce25b4..e3cf3832c5b6 100644 --- a/drivers/scsi/isci/host.c +++ b/drivers/scsi/isci/host.c @@ -650,15 +650,13 @@ static void isci_host_start_complete(struct isci_host *ihost, enum sci_status co int isci_host_scan_finished(struct Scsi_Host *shost, unsigned long time) { - struct isci_host *ihost = SHOST_TO_SAS_HA(shost)->lldd_ha; + struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost); + struct isci_host *ihost = ha->lldd_ha; if (test_bit(IHOST_START_PENDING, &ihost->flags)) return 0; - /* todo: use sas_flush_discovery once it is upstream */ - scsi_flush_work(shost); - - scsi_flush_work(shost); + sas_drain_work(ha); dev_dbg(&ihost->pdev->dev, "%s: ihost->status = %d, time = %ld\n", |