s390/dasd: fix read unit address configuration loop

Read unit address is done for all devices during online processing to read
out LCU features. This is also done after disconnect/connect a LCU.
Some older storage hardware does not provide the capability to read unit
address configuration.
This leads to a loop trying to read unit address configuration every 30
seconds. The device is still operational but logs are flooded with error
messages.

Fix the loop by recognizing a command reject saying that the suborder
for ruac is not supported.

Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c
index 157defe..6b55699 100644 (file)
--- a/drivers/s390/block/dasd_alias.c
+++ b/drivers/s390/block/dasd_alias.c
@@ -384,6 +384,29 @@ static void _remove_device_from_lcu(struct alias_lcu *lcu,
                group->next = NULL;
 };
 
+static int
+suborder_not_supported(struct dasd_ccw_req *cqr)
+{
+       char *sense;
+       char reason;
+       char msg_format;
+       char msg_no;
+
+       sense = dasd_get_sense(&cqr->irb);
+       if (!sense)
+               return 0;
+
+       reason = sense[0];
+       msg_format = (sense[7] & 0xF0);
+       msg_no = (sense[7] & 0x0F);
+
+       /* command reject, Format 0 MSG 4 - invalid parameter */
+       if ((reason == 0x80) && (msg_format == 0x00) && (msg_no == 0x04))
+               return 1;
+
+       return 0;
+}
+
 static int read_unit_address_configuration(struct dasd_device *device,
                                           struct alias_lcu *lcu)
 {
@@ -435,6 +458,8 @@ static int read_unit_address_configuration(struct dasd_device *device,
 
        do {
                rc = dasd_sleep_on(cqr);
+               if (rc && suborder_not_supported(cqr))
+                       return -EOPNOTSUPP;
        } while (rc && (cqr->retries > 0));
        if (rc) {
                spin_lock_irqsave(&lcu->lock, flags);
@@ -521,7 +546,7 @@ static void lcu_update_work(struct work_struct *work)
         * processing the data
         */
        spin_lock_irqsave(&lcu->lock, flags);
-       if (rc || (lcu->flags & NEED_UAC_UPDATE)) {
+       if ((rc && (rc != -EOPNOTSUPP)) || (lcu->flags & NEED_UAC_UPDATE)) {
                DBF_DEV_EVENT(DBF_WARNING, device, "could not update"
                            " alias data in lcu (rc = %d), retry later", rc);
                schedule_delayed_work(&lcu->ruac_data.dwork, 30*HZ);