[SCSI] megaraid_sas: support devices update flag

Driver added the Device update flag to tell LSI application driver
whether to do the device Update. LSI MegaRAID SAS application will
check this flag to decide if it needs to update the Device or not.

Signed-off-by Bo Yang <[e-mail]>
Signed-off-by: James Bottomley <[e-mail]>

drivers/scsi/megaraid/megaraid_sas.c

···
 static DECLARE_WAIT_QUEUE_HEAD(megasas_poll_wait);
 static u32 support_poll_for_event;
 static u32 megasas_dbg_lvl;
+static u32 support_device_change;
 
 /* define lock for aen poll */
 spinlock_t poll_aen_lock;
···
 static DRIVER_ATTR(support_poll_for_event, S_IRUGO,
 			megasas_sysfs_show_support_poll_for_event, NULL);
 
+ static ssize_t
+megasas_sysfs_show_support_device_change(struct device_driver *dd, char *buf)
+{
+	return sprintf(buf, "%u\n", support_device_change);
+}
+
+static DRIVER_ATTR(support_device_change, S_IRUGO,
+			megasas_sysfs_show_support_device_change, NULL);
+
 static ssize_t
 megasas_sysfs_show_dbg_lvl(struct device_driver *dd, char *buf)
 {
···
 	       MEGASAS_EXT_VERSION);
 
 	support_poll_for_event = 2;
+	support_device_change = 1;
 
 	memset(&megasas_mgmt_info, 0, sizeof(megasas_mgmt_info));
 
···
 	if (rval)
 		goto err_dcf_poll_mode_io;
 
+	rval = driver_create_file(&megasas_pci_driver.driver,
+				&driver_attr_support_device_change);
+	if (rval)
+		goto err_dcf_support_device_change;
+
 	return rval;
+
+err_dcf_support_device_change:
+	driver_remove_file(&megasas_pci_driver.driver,
+		  &driver_attr_poll_mode_io);
 
 err_dcf_poll_mode_io:
 	driver_remove_file(&megasas_pci_driver.driver,
···
 			   &driver_attr_poll_mode_io);
 	driver_remove_file(&megasas_pci_driver.driver,
 			   &driver_attr_dbg_lvl);
+	driver_remove_file(&megasas_pci_driver.driver,
+			&driver_attr_support_poll_for_event);
+	driver_remove_file(&megasas_pci_driver.driver,
+			&driver_attr_support_device_change);
 	driver_remove_file(&megasas_pci_driver.driver,
 			   &driver_attr_release_date);
 	driver_remove_file(&megasas_pci_driver.driver, &driver_attr_version);