uas: Add uas_get_tag() helper function

Factor out the mapping of scsi-tags -> uas-tags/stream-ids to a helper function
so that there is a single place where this "magic" happens.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c
index 50d2d85..3debefb 100644 (file)
--- a/drivers/usb/storage/uas.c
+++ b/drivers/usb/storage/uas.c
@@ -259,13 +259,29 @@ static void uas_sense_old(struct urb *urb, struct scsi_cmnd *cmnd)
        cmnd->result = sense_iu->status;
 }
 
+/*
+ * scsi-tags go from 0 - (nr_tags - 1), uas tags need to match stream-ids,
+ * which go from 1 - nr_streams. And we use 1 for untagged commands.
+ */
+static int uas_get_tag(struct scsi_cmnd *cmnd)
+{
+       int tag;
+
+       if (blk_rq_tagged(cmnd->request))
+               tag = cmnd->request->tag + 2;
+       else
+               tag = 1;
+
+       return tag;
+}
+
 static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *caller)
 {
        struct uas_cmd_info *ci = (void *)&cmnd->SCp;
 
        scmd_printk(KERN_INFO, cmnd, "%s %p tag %d, inflight:"
                    "%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n",
-                   caller, cmnd, cmnd->request->tag,
+                   caller, cmnd, uas_get_tag(cmnd),
                    (ci->state & SUBMIT_STATUS_URB)     ? " s-st"  : "",
                    (ci->state & ALLOC_DATA_IN_URB)     ? " a-in"  : "",
                    (ci->state & SUBMIT_DATA_IN_URB)    ? " s-in"  : "",
@@ -516,10 +532,7 @@ static struct urb *uas_alloc_cmd_urb(struct uas_dev_info *devinfo, gfp_t gfp,
                goto free;
 
        iu->iu_id = IU_ID_COMMAND;
-       if (blk_rq_tagged(cmnd->request))
-               iu->tag = cpu_to_be16(cmnd->request->tag + 2);
-       else
-               iu->tag = cpu_to_be16(1);
+       iu->tag = cpu_to_be16(uas_get_tag(cmnd));
        iu->prio_attr = UAS_SIMPLE_TAG;
        iu->len = len;
        int_to_scsilun(sdev->lun, &iu->lun);
@@ -690,17 +703,13 @@ static int uas_queuecommand_lck(struct scsi_cmnd *cmnd,
 
        memset(cmdinfo, 0, sizeof(*cmdinfo));
 
-       if (blk_rq_tagged(cmnd->request)) {
-               cmdinfo->stream = cmnd->request->tag + 2;
-       } else {
+       if (!blk_rq_tagged(cmnd->request))
                devinfo->cmnd = cmnd;
-               cmdinfo->stream = 1;
-       }
 
        cmnd->scsi_done = done;
 
-       cmdinfo->state = SUBMIT_STATUS_URB |
-                       ALLOC_CMD_URB | SUBMIT_CMD_URB;
+       cmdinfo->stream = uas_get_tag(cmnd);
+       cmdinfo->state = SUBMIT_STATUS_URB | ALLOC_CMD_URB | SUBMIT_CMD_URB;
 
        switch (cmnd->sc_data_direction) {
        case DMA_FROM_DEVICE: