Bluetooth: Don't fail RFCOMM tty writes
authorPeter Hurley <peter@hurleysoftware.com>
Mon, 10 Feb 2014 01:59:22 +0000 (20:59 -0500)
committerMarcel Holtmann <marcel@holtmann.org>
Fri, 14 Feb 2014 21:39:32 +0000 (13:39 -0800)
The tty driver api design prefers no-fail writes if the driver
write_room() method has previously indicated space is available
to accept writes. Since this is trivially possible for the
RFCOMM tty driver, do so.

Introduce rfcomm_dlc_send_noerror(), which queues but does not
schedule the krfcomm thread if the dlc is not yet connected
(and thus does not error based on the connection state).
The mtu size test is also unnecessary since the caller already
chunks the written data into mtu size.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
include/net/bluetooth/rfcomm.h
net/bluetooth/rfcomm/core.c
net/bluetooth/rfcomm/tty.c

index f8262a2783ecc313d85d5b85b00129ef05fee772..2611cc389d7d65d03cf298061bf3e4ed32c304cd 100644 (file)
@@ -238,6 +238,7 @@ int  rfcomm_dlc_open(struct rfcomm_dlc *d, bdaddr_t *src, bdaddr_t *dst,
                                                                u8 channel);
 int  rfcomm_dlc_close(struct rfcomm_dlc *d, int reason);
 int  rfcomm_dlc_send(struct rfcomm_dlc *d, struct sk_buff *skb);
+void rfcomm_dlc_send_noerror(struct rfcomm_dlc *d, struct sk_buff *skb);
 int  rfcomm_dlc_set_modem_status(struct rfcomm_dlc *d, u8 v24_sig);
 int  rfcomm_dlc_get_modem_status(struct rfcomm_dlc *d, u8 *v24_sig);
 void rfcomm_dlc_accept(struct rfcomm_dlc *d);
index b727cd97c5a28253a63cdb53b7f659602d8df4f9..21e15318937c31e8d7b6c8f286036dfa2ec22300 100644 (file)
@@ -569,6 +569,20 @@ int rfcomm_dlc_send(struct rfcomm_dlc *d, struct sk_buff *skb)
        return len;
 }
 
+void rfcomm_dlc_send_noerror(struct rfcomm_dlc *d, struct sk_buff *skb)
+{
+       int len = skb->len;
+
+       BT_DBG("dlc %p mtu %d len %d", d, d->mtu, len);
+
+       rfcomm_make_uih(skb, d->addr);
+       skb_queue_tail(&d->tx_queue, skb);
+
+       if (d->state == BT_CONNECTED &&
+           !test_bit(RFCOMM_TX_THROTTLED, &d->flags))
+               rfcomm_schedule();
+}
+
 void __rfcomm_dlc_throttle(struct rfcomm_dlc *d)
 {
        BT_DBG("dlc %p state %ld", d, d->state);
index f6b9f0c4c29e49bb846319e3809eaf46aa5071ac..af775f35c019f088e4467837e0887170e269e72c 100644 (file)
@@ -374,14 +374,10 @@ static void rfcomm_set_owner_w(struct sk_buff *skb, struct rfcomm_dev *dev)
 
 static struct sk_buff *rfcomm_wmalloc(struct rfcomm_dev *dev, unsigned long size, gfp_t priority)
 {
-       if (atomic_read(&dev->wmem_alloc) < rfcomm_room(dev->dlc)) {
-               struct sk_buff *skb = alloc_skb(size, priority);
-               if (skb) {
-                       rfcomm_set_owner_w(skb, dev);
-                       return skb;
-               }
-       }
-       return NULL;
+       struct sk_buff *skb = alloc_skb(size, priority);
+       if (skb)
+               rfcomm_set_owner_w(skb, dev);
+       return skb;
 }
 
 /* ---- Device IOCTLs ---- */
@@ -786,7 +782,7 @@ static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, in
        struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
        struct rfcomm_dlc *dlc = dev->dlc;
        struct sk_buff *skb;
-       int err = 0, sent = 0, size;
+       int sent = 0, size;
 
        BT_DBG("tty %p count %d", tty, count);
 
@@ -794,7 +790,6 @@ static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, in
                size = min_t(uint, count, dlc->mtu);
 
                skb = rfcomm_wmalloc(dev, size + RFCOMM_SKB_RESERVE, GFP_ATOMIC);
-
                if (!skb)
                        break;
 
@@ -802,17 +797,13 @@ static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, in
 
                memcpy(skb_put(skb, size), buf + sent, size);
 
-               err = rfcomm_dlc_send(dlc, skb);
-               if (err < 0) {
-                       kfree_skb(skb);
-                       break;
-               }
+               rfcomm_dlc_send_noerror(dlc, skb);
 
                sent  += size;
                count -= size;
        }
 
-       return sent ? sent : err;
+       return sent;
 }
 
 static int rfcomm_tty_write_room(struct tty_struct *tty)