s390/dasd: make number of retries configurable

Instead of having the number of retries hard-coded in the various
functions we should be using a default retry value, which can
be modified via sysfs.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index 0785bd9..ad42075 100644
--- a/drivers/s390/block/dasd_int.h
+++ b/drivers/s390/block/dasd_int.h
@@ -224,6 +224,8 @@
 /* default expiration time*/
 #define DASD_EXPIRES	  300
 #define DASD_EXPIRES_MAX  40000000
+#define DASD_RETRIES	  256
+#define DASD_RETRIES_MAX  32768
 
 /* per dasd_ccw_req flags */
 #define DASD_CQR_FLAGS_USE_ERP   0	/* use ERP for this request */
@@ -466,6 +468,7 @@
 
 	/* default expiration time in s */
 	unsigned long default_expires;
+	unsigned long default_retries;
 
 	struct dentry *debugfs_dentry;
 	struct dasd_profile profile;