[SCSI] mpt2sas: Fix for staged device discovery functionality of driver not working

This patch provides a command line option to disable "Port enable" during
the driver load.

The objective of this command line option is to load the driver and do
all the necessary initialization excluding port enable(i.e. delay
device discovery)

Signed-off-by: Sreekanth Reddy <sreekanth.reddy@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

diff --git a/drivers/scsi/mpt2sas/mpt2sas_scsih.c b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
index ab3d9d3e805f0b2b3cf9728860b85e1699b0e963..66c773662694c590623b0724d60801afb2850526 100644 (file)
--- a/drivers/scsi/mpt2sas/mpt2sas_scsih.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
@@ -119,6 +119,10 @@ module_param(diag_buffer_enable, int, 0);
 MODULE_PARM_DESC(diag_buffer_enable, " post diag buffers "
        "(TRACE=1/SNAPSHOT=2/EXTENDED=4/default=0)");
 
+static int disable_discovery = -1;
+module_param(disable_discovery, int, 0);
+MODULE_PARM_DESC(disable_discovery, " disable discovery ");
+
 /**
  * struct sense_info - common structure for obtaining sense keys
  * @skey: sense key
@@ -5973,8 +5977,14 @@ _scsih_sas_discovery_event(struct MPT2SAS_ADAPTER *ioc,
 #endif
 
        if (event_data->ReasonCode == MPI2_EVENT_SAS_DISC_RC_STARTED &&
-           !ioc->sas_hba.num_phys)
+           !ioc->sas_hba.num_phys) {
+               if (disable_discovery > 0 && ioc->shost_recovery) {
+                       /* Wait for the reset to complete */
+                       while (ioc->shost_recovery)
+                               ssleep(1);
+               }
                _scsih_sas_host_add(ioc);
+       }
 }
 
 /**
@@ -7929,6 +7939,9 @@ _scsih_scan_start(struct Scsi_Host *shost)
        if (diag_buffer_enable != -1 && diag_buffer_enable != 0)
                mpt2sas_enable_diag_buffer(ioc, diag_buffer_enable);
 
+       if (disable_discovery > 0)
+               return;
+
        ioc->start_scan = 1;
        rc = mpt2sas_port_enable(ioc);
 
@@ -7950,6 +7963,12 @@ _scsih_scan_finished(struct Scsi_Host *shost, unsigned long time)
 {
        struct MPT2SAS_ADAPTER *ioc = shost_priv(shost);
 
+       if (disable_discovery > 0) {
+               ioc->is_driver_loading = 0;
+               ioc->wait_for_discovery_to_complete = 0;
+               return 1;
+       }
+
        if (time >= (300 * HZ)) {
                ioc->base_cmds.status = MPT2_CMD_NOT_USED;
                printk(MPT2SAS_INFO_FMT "port enable: FAILED with timeout "