diff options
| author | Peter Hurley <peter@hurleysoftware.com> | 2014-02-09 20:59:23 -0500 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2014-02-14 13:39:32 -0800 |
| commit | b16b4351313fb89ccb4c227d432d16aa32ffec72 (patch) | |
| tree | 4f5b863566aa2b255cd99b928bca2df96767deb8 /net | |
| parent | 72e5108c6d637ea2f4c0e64b09621a79f363b664 (diff) | |
| download | linux-b16b4351313fb89ccb4c227d432d16aa32ffec72.tar.bz2 | |
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')
| -rw-r--r-- | net/bluetooth/rfcomm/tty.c | 27 |
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; } |