[36/50] incubator-mynewt-core git commit: nimble/l2cap: Add initial credits calculations

[ma...@apache.org]

nimble/l2cap: Add initial credits calculations

With this patch we calculate initial credits in that way that
peer device is able to send full SDU by fill up fully LE frames.

If it happens that peer is not filling up LE Frames, there is mechanism
to handling it already in receiving function


Project: http://git-wip-us.apache.org/repos/asf/incubator-mynewt-core/repo
Commit: http://git-wip-us.apache.org/repos/asf/incubator-mynewt-core/commit/750707ba
Tree: http://git-wip-us.apache.org/repos/asf/incubator-mynewt-core/tree/750707ba
Diff: http://git-wip-us.apache.org/repos/asf/incubator-mynewt-core/diff/750707ba

Branch: refs/heads/master
Commit: 750707ba60915ea182d416c8289324d16af8fa64
Parents: 6963daf
Author: \u0141ukasz Rymanowski <lu...@codecoup.pl>
Authored: Fri Mar 3 11:30:45 2017 +0100
Committer: \u0141ukasz Rymanowski <lu...@codecoup.pl>
Committed: Fri Mar 3 12:40:43 2017 +0100

----------------------------------------------------------------------
 net/nimble/host/src/ble_l2cap_coc.c  | 16 ++++++++++------
 net/nimble/host/src/ble_l2cap_priv.h |  1 +
 2 files changed, 11 insertions(+), 6 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/incubator-mynewt-core/blob/750707ba/net/nimble/host/src/ble_l2cap_coc.c
----------------------------------------------------------------------
diff --git a/net/nimble/host/src/ble_l2cap_coc.c b/net/nimble/host/src/ble_l2cap_coc.c
index f7ecef4..fbfbf31 100644
--- a/net/nimble/host/src/ble_l2cap_coc.c
+++ b/net/nimble/host/src/ble_l2cap_coc.c
@@ -249,9 +249,14 @@ ble_l2cap_coc_chan_alloc(uint16_t conn_handle, uint16_t psm, uint16_t mtu,
     chan->my_mtu = BLE_L2CAP_COC_MTU;
     chan->rx_fn = ble_l2cap_coc_rx_fn;
     chan->coc_rx.mtu = mtu;
-    chan->coc_rx.credits = 10; /* FIXME Calculate it */
     chan->coc_rx.sdu = sdu_rx;
 
+    /* Number of credits should allow to send full SDU with on given
+     * L2CAP MTU
+     */
+    chan->coc_rx.credits = (mtu + (chan->my_mtu - 1) / 2) / chan->my_mtu;
+
+    chan->initial_credits = chan->coc_rx.credits;
     return chan;
 }
 
@@ -459,13 +464,12 @@ ble_l2cap_coc_recv_ready(struct ble_l2cap_chan *chan, struct os_mbuf *sdu_rx)
         return;
     }
 
-    /* FIXME 10 is hardcoded - make it better.
-     * We want to back only that much credits which remote side is missing
+    /* We want to back only that much credits which remote side is missing
      * to be able to send complete SDU.
      */
-    if (chan->coc_rx.credits < 10) {
-        ble_l2cap_sig_le_credits(chan, 10 - chan->coc_rx.credits);
-        chan->coc_rx.credits = 10;
+    if (chan->coc_rx.credits < c->initial_credits) {
+        ble_l2cap_sig_le_credits(chan, c->initial_credits - chan->coc_rx.credits);
+        chan->coc_rx.credits = c->initial_credits;
     }
 
     ble_hs_unlock();

http://git-wip-us.apache.org/repos/asf/incubator-mynewt-core/blob/750707ba/net/nimble/host/src/ble_l2cap_priv.h
----------------------------------------------------------------------
diff --git a/net/nimble/host/src/ble_l2cap_priv.h b/net/nimble/host/src/ble_l2cap_priv.h
index 5db63c3..1d035e8 100644
--- a/net/nimble/host/src/ble_l2cap_priv.h
+++ b/net/nimble/host/src/ble_l2cap_priv.h
@@ -82,6 +82,7 @@ struct ble_l2cap_chan {
     uint16_t psm;
     struct ble_l2cap_coc_endpoint coc_rx;
     struct ble_l2cap_coc_endpoint coc_tx;
+    uint16_t initial_credits;
     ble_l2cap_event_fn *cb;
     void *cb_arg;
 #endif