uwb: improved MAS allocator and reservation conflict handling

Greatly enhance the MAS allocator:
  - Handle row and column reservations.
  - Permit all the available MAS to be allocated.
  - Follows the WiMedia rules on MAS selection.

Take appropriate action when reservation conflicts are detected.
  - Correctly identify which reservation wins the conflict.
  - Protect alien BP reservations.
  - If an owned reservation loses, resize/move it.
  - Follow the backoff procedure before requesting additional MAS.

When reservations are terminated, move the remaining reservations (if
necessary) so they keep following the MAS allocation rules.

Signed-off-by: Stefano Panella <stefano.panella@csr.com>
Signed-off-by: David Vrabel <david.vrabel@csr.com>

1 files changed, 7 insertions, 6 deletions

diff --git a/drivers/usb/wusbcore/reservation.c b/drivers/usb/wusbcore/reservation.c
index 7b6525dac2f1..c37e4f83e54a 100644
--- a/drivers/usb/wusbcore/reservation.c
+++ b/drivers/usb/wusbcore/reservation.c
@@ -48,13 +48,15 @@ static void wusbhc_rsv_complete_cb(struct uwb_rsv *rsv)
 {
         struct wusbhc *wusbhc = rsv->pal_priv;
         struct device *dev = wusbhc->dev;
+        struct uwb_mas_bm mas;
         char buf[72];
 
         switch (rsv->state) {
         case UWB_RSV_STATE_O_ESTABLISHED:
-                bitmap_scnprintf(buf, sizeof(buf), rsv->mas.bm, UWB_NUM_MAS);
+                uwb_rsv_get_usable_mas(rsv, &mas);
+                bitmap_scnprintf(buf, sizeof(buf), mas.bm, UWB_NUM_MAS);
                 dev_dbg(dev, "established reservation: %s\n", buf);
-                wusbhc_bwa_set(wusbhc, rsv->stream, &rsv->mas);
+                wusbhc_bwa_set(wusbhc, rsv->stream, &mas);
                 break;
         case UWB_RSV_STATE_NONE:
                 dev_dbg(dev, "removed reservation\n");
@@ -85,13 +87,12 @@ int wusbhc_rsv_establish(struct wusbhc *wusbhc)
         bcid.data[0] = wusbhc->cluster_id;
         bcid.data[1] = 0;
 
-        rsv->owner = &rc->uwb_dev;
         rsv->target.type = UWB_RSV_TARGET_DEVADDR;
         rsv->target.devaddr = bcid;
         rsv->type = UWB_DRP_TYPE_PRIVATE;
-        rsv->max_mas = 256;
-        rsv->min_mas = 16;  /* one MAS per zone? */
-        rsv->sparsity = 16; /* at least one MAS in each zone? */
+        rsv->max_mas = 256; /* try to get as much as possible */
+        rsv->min_mas = 15;  /* one MAS per zone */
+        rsv->max_interval = 1; /* max latency is one zone */
         rsv->is_multicast = true;
 
         ret = uwb_rsv_establish(rsv);