Bluetooth: Use non-flushable pb flag by default for ACL data on capable chipsets.

With Bluetooth 2.1 ACL packets can be flushable or non-flushable. This commit
makes ACL data packets non-flushable by default on compatible chipsets, and
adds the L2CAP_LM_FLUSHABLE socket option to explicitly request flushable ACL
data packets for a given L2CAP socket. This is useful for A2DP data which can
be safely discarded if it can not be delivered within a short time (while
other ACL data should not be discarded).

Note that making ACL data flushable has no effect unless the automatic flush
timeout for that ACL link is changed from its default of 0 (infinite).

Change-Id: Ie3d4befdeaefb8c979de7ae603ff5ec462b3483c
Signed-off-by: Nick Pelly <npelly@google.com>

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index b5c80f86a1eea3e7e466683796229e9771c45614..90076fbe3446451c20de3bb5c5d6f4f055bbadd1 100644 (file)
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -152,11 +152,14 @@ enum {
                        EDR_ESCO_MASK)
 
 /* ACL flags */
+#define ACL_START_NO_FLUSH     0x00
 #define ACL_CONT               0x01
 #define ACL_START              0x02
 #define ACL_ACTIVE_BCAST       0x04
 #define ACL_PICO_BCAST         0x08
 
+#define ACL_PB_MASK    (ACL_CONT | ACL_START)
+
 /* Baseband links */
 #define SCO_LINK       0x00
 #define ACL_LINK       0x01
@@ -195,6 +198,7 @@ enum {
 #define LMP_EDR_ESCO_3M        0x40
 #define LMP_EDR_3S_ESCO        0x80
 
+#define LMP_NO_FLUSH   0x01
 #define LMP_SIMPLE_PAIR        0x08
 
 /* Connection modes */

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 075002b2cd38bad239a8cc5c8ab401d5c23221d7..1ce134720cfeb197e8a2837563dca8bd362a35da 100644 (file)
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -459,6 +459,7 @@ void hci_conn_del_sysfs(struct hci_conn *conn);
 #define lmp_sniffsubr_capable(dev) ((dev)->features[5] & LMP_SNIFF_SUBR)
 #define lmp_esco_capable(dev)      ((dev)->features[3] & LMP_ESCO)
 #define lmp_ssp_capable(dev)       ((dev)->features[6] & LMP_SIMPLE_PAIR)
+#define lmp_no_flush_capable(dev)  ((dev)->features[6] & LMP_NO_FLUSH)
 
 /* ----- HCI protocols ----- */
 struct hci_proto {

diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index 6c241444f902800baf1c4cd16aa89d767d751065..8f8e648032e8a0a487da5c71dcaa9c33d174e924 100644 (file)
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -75,6 +75,7 @@ struct l2cap_conninfo {
 #define L2CAP_LM_TRUSTED       0x0008
 #define L2CAP_LM_RELIABLE      0x0010
 #define L2CAP_LM_SECURE                0x0020
+#define L2CAP_LM_FLUSHABLE     0x0040
 
 /* L2CAP command codes */
 #define L2CAP_COMMAND_REJ      0x01
@@ -327,6 +328,7 @@ struct l2cap_pinfo {
        __u8            sec_level;
        __u8            role_switch;
        __u8            force_reliable;
+       __u8            flushable;
 
        __u8            conf_req[64];
        __u8            conf_len;

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index c52f091ee6de2c4b1e81f68363086e2af4a51660..a49aa2bf97f3e184c6acbc7d799c4dcdc1a049f9 100644 (file)
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1367,7 +1367,7 @@ void hci_send_acl(struct hci_conn *conn, struct sk_buff *skb, __u16 flags)
 
        skb->dev = (void *) hdev;
        bt_cb(skb)->pkt_type = HCI_ACLDATA_PKT;
-       hci_add_acl_hdr(skb, conn->handle, flags | ACL_START);
+       hci_add_acl_hdr(skb, conn->handle, flags);
 
        if (!(list = skb_shinfo(skb)->frag_list)) {
                /* Non fragmented */
@@ -1384,12 +1384,14 @@ void hci_send_acl(struct hci_conn *conn, struct sk_buff *skb, __u16 flags)
                spin_lock_bh(&conn->data_q.lock);
 
                __skb_queue_tail(&conn->data_q, skb);
+               flags &= ~ACL_PB_MASK;
+               flags |= ACL_CONT;
                do {
                        skb = list; list = list->next;
 
                        skb->dev = (void *) hdev;
                        bt_cb(skb)->pkt_type = HCI_ACLDATA_PKT;
-                       hci_add_acl_hdr(skb, conn->handle, flags | ACL_CONT);
+                       hci_add_acl_hdr(skb, conn->handle, flags);
 
                        BT_DBG("%s frag %p len %d", hdev->name, skb, skb->len);
 

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 001a638fe2c04dd126180ad3cea1c116e59c3944..0ac962b978e153bf6d9b8ac63ac5f6f88958d991 100644 (file)
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -354,13 +354,19 @@ static inline u8 l2cap_get_ident(struct l2cap_conn *conn)
 static inline void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len, void *data)
 {
        struct sk_buff *skb = l2cap_build_cmd(conn, code, ident, len, data);
+       u8 flags;
 
        BT_DBG("code 0x%2.2x", code);
 
        if (!skb)
                return;
 
-       hci_send_acl(conn->hcon, skb, 0);
+       if (lmp_no_flush_capable(conn->hcon->hdev))
+               flags = ACL_START_NO_FLUSH;
+       else
+               flags = ACL_START;
+
+       hci_send_acl(conn->hcon, skb, flags);
 }
 
 static inline void l2cap_send_sframe(struct l2cap_pinfo *pi, u16 control)
@@ -900,6 +906,7 @@ static void l2cap_sock_init(struct sock *sk, struct sock *parent)
                pi->sec_level = l2cap_pi(parent)->sec_level;
                pi->role_switch = l2cap_pi(parent)->role_switch;
                pi->force_reliable = l2cap_pi(parent)->force_reliable;
+               pi->flushable = l2cap_pi(parent)->flushable;
        } else {
                pi->imtu = L2CAP_DEFAULT_MTU;
                pi->omtu = 0;
@@ -915,6 +922,7 @@ static void l2cap_sock_init(struct sock *sk, struct sock *parent)
                pi->sec_level = BT_SECURITY_LOW;
                pi->role_switch = 0;
                pi->force_reliable = 0;
+               pi->flushable = 0;
        }
 
        /* Default config options */
@@ -1433,10 +1441,17 @@ static void l2cap_drop_acked_frames(struct sock *sk)
 static inline void l2cap_do_send(struct sock *sk, struct sk_buff *skb)
 {
        struct l2cap_pinfo *pi = l2cap_pi(sk);
+       struct hci_conn *hcon = pi->conn->hcon;
+       u16 flags;
 
        BT_DBG("sk %p, skb %p len %d", sk, skb, skb->len);
 
-       hci_send_acl(pi->conn->hcon, skb, 0);
+       if (lmp_no_flush_capable(hcon->hdev) && !l2cap_pi(sk)->flushable)
+               flags = ACL_START_NO_FLUSH;
+       else
+               flags = ACL_START;
+
+       hci_send_acl(hcon, skb, flags);
 }
 
 static void l2cap_streaming_send(struct sock *sk)
@@ -2016,6 +2031,7 @@ static int l2cap_sock_setsockopt_old(struct socket *sock, int optname, char __us
 
                l2cap_pi(sk)->role_switch    = (opt & L2CAP_LM_MASTER);
                l2cap_pi(sk)->force_reliable = (opt & L2CAP_LM_RELIABLE);
+               l2cap_pi(sk)->flushable = (opt & L2CAP_LM_FLUSHABLE);
                break;
 
        default:
@@ -2146,6 +2162,9 @@ static int l2cap_sock_getsockopt_old(struct socket *sock, int optname, char __us
                if (l2cap_pi(sk)->force_reliable)
                        opt |= L2CAP_LM_RELIABLE;
 
+               if (l2cap_pi(sk)->flushable)
+                       opt |= L2CAP_LM_FLUSHABLE;
+
                if (put_user(opt, (u32 __user *) optval))
                        err = -EFAULT;
                break;
@@ -4645,7 +4664,7 @@ static int l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 fl
 
        BT_DBG("conn %p len %d flags 0x%x", conn, skb->len, flags);
 
-       if (flags & ACL_START) {
+       if (!(flags & ACL_CONT)) {
                struct l2cap_hdr *hdr;
                int len;