staging: ozwpan: Drop oldest ISOC frame instead of dropping latest.

In case of ISOC transfer, if TX queue is full then we start
dropping latest frame, instead we should drop oldest frame &
add latest frame to TX queue.

Signed-off-by: Rupesh Gujare <rupesh.gujare@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/ozwpan/ozpd.c b/drivers/staging/ozwpan/ozpd.c
index 86876bda29a5f829e6b585234c87376b77b37a3c..17fd7b2aa88e4af7c1fa75b4c1f55b506450d979 100644 (file)
--- a/drivers/staging/ozwpan/ozpd.c
+++ b/drivers/staging/ozwpan/ozpd.c
@@ -844,9 +844,20 @@ int oz_send_isoc_unit(struct oz_pd *pd, u8 ep_num, const u8 *data, int len)
                        struct oz_tx_frame *isoc_unit = NULL;
                        int nb = pd->nb_queued_isoc_frames;
                        if (nb >= pd->isoc_latency) {
+                               struct list_head *e;
+                               struct oz_tx_frame *f;
                                oz_dbg(TX_FRAMES, "Dropping ISOC Unit nb= %d\n",
                                       nb);
-                               goto out;
+                               spin_lock(&pd->tx_frame_lock);
+                               list_for_each(e, &pd->tx_queue) {
+                                       f = container_of(e, struct oz_tx_frame,
+                                                                       link);
+                                       if (f->skb != NULL) {
+                                               oz_tx_isoc_free(pd, f);
+                                               break;
+                                       }
+                               }
+                               spin_unlock(&pd->tx_frame_lock);
                        }
                        isoc_unit = oz_tx_frame_alloc(pd);
                        if (isoc_unit == NULL)