[SCSI] zfcp: fix: allow more time for adapter initialization

From: Maxim Shchetynin <maxim@de.ibm.com>

Extend the time for adapter initialization: In case of protocol
status HOST_CONNECTION_INITIALIZING for the exchange config data
command do a first retry in 1 second, then double the sleep time for
each following retry until recovery exceeds 2 minutes. The old
behaviour of allowing 6 retries with .5 seconds delay between retries
was insufficient and qdio queues were shut down too erarly.

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

2 files changed, 17 insertions, 14 deletions

diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index ead324019ff2..08369b9dad68 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -149,8 +149,10 @@ typedef u32 scsi_lun_t;
 #define FSF_QTCB_UNSOLICITED_STATUS             0x6305
 #define ZFCP_STATUS_READ_FAILED_THRESHOLD       3
 #define ZFCP_STATUS_READS_RECOM                 FSF_STATUS_READS_RECOM
-#define ZFCP_EXCHANGE_CONFIG_DATA_RETRIES       6
-#define ZFCP_EXCHANGE_CONFIG_DATA_SLEEP         50
+
+/* Do 1st retry in 1 second, then double the timeout for each following retry */
+#define ZFCP_EXCHANGE_CONFIG_DATA_FIRST_SLEEP   100
+#define ZFCP_EXCHANGE_CONFIG_DATA_RETRIES       7
 
 /* timeout value for "default timer" for fsf requests */
 #define ZFCP_FSF_REQUEST_TIMEOUT (60*HZ);
diff --git a/drivers/s390/scsi/zfcp_erp.c b/drivers/s390/scsi/zfcp_erp.c
index 53ebc1cdfe2d..60ba1ba112d6 100644
--- a/drivers/s390/scsi/zfcp_erp.c
+++ b/drivers/s390/scsi/zfcp_erp.c
@@ -2286,12 +2286,12 @@ zfcp_erp_adapter_strategy_open_fsf_xconfig(struct zfcp_erp_action *erp_action)
 {
         int retval = ZFCP_ERP_SUCCEEDED;
         int retries;
+        int sleep = ZFCP_EXCHANGE_CONFIG_DATA_FIRST_SLEEP;
         struct zfcp_adapter *adapter = erp_action->adapter;
 
         atomic_clear_mask(ZFCP_STATUS_ADAPTER_XCONFIG_OK, &adapter->status);
-        retries = ZFCP_EXCHANGE_CONFIG_DATA_RETRIES;
 
-        do {
+        for (retries = ZFCP_EXCHANGE_CONFIG_DATA_RETRIES; retries; retries--) {
                 atomic_clear_mask(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
                                   &adapter->status);
                 ZFCP_LOG_DEBUG("Doing exchange config data\n");
@@ -2329,16 +2329,17 @@ zfcp_erp_adapter_strategy_open_fsf_xconfig(struct zfcp_erp_action *erp_action)
                                       zfcp_get_busid_by_adapter(adapter));
                         break;
                 }
-                if (atomic_test_mask(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
-                                     &adapter->status)) {
-                        ZFCP_LOG_DEBUG("host connection still initialising... "
-                                       "waiting and retrying...\n");
-                        /* sleep a little bit before retry */
-                        msleep(jiffies_to_msecs(ZFCP_EXCHANGE_CONFIG_DATA_SLEEP));
-                }
-        } while ((retries--) &&
-                 atomic_test_mask(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
-                                  &adapter->status));
+
+                if (!atomic_test_mask(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
+                                     &adapter->status))
+                        break;
+
+                ZFCP_LOG_DEBUG("host connection still initialising... "
+                               "waiting and retrying...\n");
+                /* sleep a little bit before retry */
+                msleep(jiffies_to_msecs(sleep));
+                sleep *= 2;
+        }
 
         if (!atomic_test_mask(ZFCP_STATUS_ADAPTER_XCONFIG_OK,
                               &adapter->status)) {