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authorPeter Hurley <peter@hurleysoftware.com>2014-02-09 20:59:23 -0500
committerMarcel Holtmann <marcel@holtmann.org>2014-02-14 13:39:32 -0800
commitb16b4351313fb89ccb4c227d432d16aa32ffec72 (patch)
tree4f5b863566aa2b255cd99b928bca2df96767deb8 /net/bluetooth/rfcomm
parent72e5108c6d637ea2f4c0e64b09621a79f363b664 (diff)
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Bluetooth: Refactor write_room() calculation
Compute the amount of space available for a single write() within rfcomm_room(); clamp to 0 for negative values. Note this patch does not change the result of the computation. Report the amount of room returned in the debug printk. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Tested-By: Alexander Holler <holler@ahsoftware.de> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/bluetooth/rfcomm')
-rw-r--r--net/bluetooth/rfcomm/tty.c27
1 files changed, 15 insertions, 12 deletions
diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c
index af775f35c019..3f44195c04ad 100644
--- a/net/bluetooth/rfcomm/tty.c
+++ b/net/bluetooth/rfcomm/tty.c
@@ -348,11 +348,18 @@ static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
}
/* ---- Send buffer ---- */
-static inline unsigned int rfcomm_room(struct rfcomm_dlc *dlc)
+static inline unsigned int rfcomm_room(struct rfcomm_dev *dev)
{
- /* We can't let it be zero, because we don't get a callback
- when tx_credits becomes nonzero, hence we'd never wake up */
- return dlc->mtu * (dlc->tx_credits?:1);
+ struct rfcomm_dlc *dlc = dev->dlc;
+
+ /* The limit is bogus; the number of packets which can
+ * currently be sent by the krfcommd thread has no relevance
+ * to the number of packets which can be queued on the dlc's
+ * tx queue.
+ */
+ int limit = dlc->mtu * (dlc->tx_credits?:1);
+
+ return max(0, limit - atomic_read(&dev->wmem_alloc));
}
static void rfcomm_wfree(struct sk_buff *skb)
@@ -809,16 +816,12 @@ static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, in
static int rfcomm_tty_write_room(struct tty_struct *tty)
{
struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
- int room;
+ int room = 0;
- BT_DBG("tty %p", tty);
-
- if (!dev || !dev->dlc)
- return 0;
+ if (dev && dev->dlc)
+ room = rfcomm_room(dev);
- room = rfcomm_room(dev->dlc) - atomic_read(&dev->wmem_alloc);
- if (room < 0)
- room = 0;
+ BT_DBG("tty %p room %d", tty, room);
return room;
}