storage: Fix bus scan and multi-LUN support for SCM eUSCSI devices

[mirror_ubuntu-artful-kernel.git] / drivers / usb / storage / usb.c

diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index 9d66ce62542e1ed620c6d815b07f93f32a2528c7..d468d02179f4707d308192ed3578665a41ee96f9 100644 (file)
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -884,7 +884,9 @@ static void usb_stor_scan_dwork(struct work_struct *work)
        dev_dbg(dev, "starting scan\n");
 
        /* For bulk-only devices, determine the max LUN value */
-       if (us->protocol == USB_PR_BULK && !(us->fflags & US_FL_SINGLE_LUN)) {
+       if (us->protocol == USB_PR_BULK &&
+           !(us->fflags & US_FL_SINGLE_LUN) &&
+           !(us->fflags & US_FL_SCM_MULT_TARG)) {
                mutex_lock(&us->dev_mutex);
                us->max_lun = usb_stor_Bulk_max_lun(us);
                mutex_unlock(&us->dev_mutex);
@@ -983,21 +985,31 @@ int usb_stor_probe2(struct us_data *us)
        usb_stor_dbg(us, "Transport: %s\n", us->transport_name);
        usb_stor_dbg(us, "Protocol: %s\n", us->protocol_name);
 
+       if (us->fflags & US_FL_SCM_MULT_TARG) {
+               /*
+                * SCM eUSCSI bridge devices can have different numbers
+                * of LUNs on different targets; allow all to be probed.
+                */
+               us->max_lun = 7;
+               /* The eUSCSI itself has ID 7, so avoid scanning that */
+               us_to_host(us)->this_id = 7;
+               /* max_id is 8 initially, so no need to set it here */
+       } else {
+               /* In the normal case there is only a single target */
+               us_to_host(us)->max_id = 1;
+               /*
+                * Like Windows, we won't store the LUN bits in CDB[1] for
+                * SCSI-2 devices using the Bulk-Only transport (even though
+                * this violates the SCSI spec).
+                */
+               if (us->transport == usb_stor_Bulk_transport)
+                       us_to_host(us)->no_scsi2_lun_in_cdb = 1;
+       }
+
        /* fix for single-lun devices */
        if (us->fflags & US_FL_SINGLE_LUN)
                us->max_lun = 0;
 
-       if (!(us->fflags & US_FL_SCM_MULT_TARG))
-               us_to_host(us)->max_id = 1;
-
-       /*
-        * Like Windows, we won't store the LUN bits in CDB[1] for SCSI-2
-        * devices using the Bulk-Only transport (even though this violates
-        * the SCSI spec).
-        */
-       if (us->transport == usb_stor_Bulk_transport)
-               us_to_host(us)->no_scsi2_lun_in_cdb = 1;
-
        /* Find the endpoints and calculate pipe values */
        result = get_pipes(us);
        if (result)