[SCSI] zfcp: Use status_read_buf_num provided by FCP channel

The FCP channel provides the number of status read buffers to issue.
Use the provided number instead of the hardcoded number in zfcp.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

5 files changed, 6 insertions, 3 deletions

diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index abf33db647ff..e331df2122f7 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -425,7 +425,8 @@ int zfcp_status_read_refill(struct zfcp_adapter *adapter)
 {
         while (atomic_read(&adapter->stat_miss) > 0)
                 if (zfcp_fsf_status_read(adapter->qdio)) {
-                        if (atomic_read(&adapter->stat_miss) >= 16) {
+                        if (atomic_read(&adapter->stat_miss) >=
+                            adapter->stat_read_buf_num) {
                                 zfcp_erp_adapter_reopen(adapter, 0, "axsref1",
                                                         NULL);
                                 return 1;
diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index 0b2ae60a6f9f..9fa1b064893e 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -164,6 +164,7 @@ struct zfcp_adapter {
                                                       stack abort/command
                                                       completion races */
         atomic_t                stat_miss;         /* # missing status reads*/
+        unsigned int            stat_read_buf_num;
         struct work_struct      stat_work;
         atomic_t                status;            /* status of this adapter */
         struct list_head        erp_ready_head;    /* error recovery for this
diff --git a/drivers/s390/scsi/zfcp_erp.c b/drivers/s390/scsi/zfcp_erp.c
index 0be5e7ea2828..e3dbeda97179 100644
--- a/drivers/s390/scsi/zfcp_erp.c
+++ b/drivers/s390/scsi/zfcp_erp.c
@@ -714,7 +714,7 @@ static int zfcp_erp_adapter_strategy_open_fsf(struct zfcp_erp_action *act)
         if (zfcp_erp_adapter_strategy_open_fsf_xport(act) == ZFCP_ERP_FAILED)
                 return ZFCP_ERP_FAILED;
 
-        atomic_set(&act->adapter->stat_miss, 16);
+        atomic_set(&act->adapter->stat_miss, act->adapter->stat_read_buf_num);
         if (zfcp_status_read_refill(act->adapter))
                 return ZFCP_ERP_FAILED;
 
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 3822f22b8150..9f90b03ac97d 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -496,6 +496,7 @@ static int zfcp_fsf_exchange_config_evaluate(struct zfcp_fsf_req *req)
 
         adapter->hydra_version = bottom->adapter_type;
         adapter->timer_ticks = bottom->timer_interval;
+        adapter->stat_read_buf_num = max(bottom->status_read_buf_num, (u16)16);
 
         if (fc_host_permanent_port_name(shost) == -1)
                 fc_host_permanent_port_name(shost) = fc_host_port_name(shost);
diff --git a/drivers/s390/scsi/zfcp_fsf.h b/drivers/s390/scsi/zfcp_fsf.h
index 4008bd786793..519083fd6e89 100644
--- a/drivers/s390/scsi/zfcp_fsf.h
+++ b/drivers/s390/scsi/zfcp_fsf.h
@@ -366,7 +366,7 @@ struct fsf_qtcb_bottom_config {
         u32 adapter_type;
         u8 res0;
         u8 peer_d_id[3];
-        u8 res1[2];
+        u16 status_read_buf_num;
         u16 timer_interval;
         u8 res2[9];
         u8 s_id[3];