| From | Greg Kroah-Hartman <> | Subject | [ 36/52] n_gsm: uplink SKBs accumulate on list | Date | Thu, 4 Oct 2012 14:21:27 -0700 |
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3.4-stable review patch. If anyone has any objections, please let me know.
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From: Russ Gorby <russ.gorby@intel.com>
commit 192b6041e75bb4a2aae73834037038cea139a92d upstream.
gsm_dlci_data_kick will not call any output function if tx_bytes > THRESH_LO furthermore it will call the output function only once if tx_bytes == 0 If the size of the IP writes are on the order of THRESH_LO we can get into a situation where skbs accumulate on the outbound list being starved for events to call the output function.
gsm_dlci_data_kick now calls the sweep function when tx_bytes==0
Signed-off-by: Russ Gorby <russ.gorby@intel.com> Tested-by: Kappel, LaurentX <laurentx.kappel@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/tty/n_gsm.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
--- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -971,16 +971,19 @@ static void gsm_dlci_data_sweep(struct g static void gsm_dlci_data_kick(struct gsm_dlci *dlci) { unsigned long flags; + int sweep; spin_lock_irqsave(&dlci->gsm->tx_lock, flags); /* If we have nothing running then we need to fire up */ + sweep = (dlci->gsm->tx_bytes < TX_THRESH_LO); if (dlci->gsm->tx_bytes == 0) { if (dlci->net) gsm_dlci_data_output_framed(dlci->gsm, dlci); else gsm_dlci_data_output(dlci->gsm, dlci); - } else if (dlci->gsm->tx_bytes < TX_THRESH_LO) - gsm_dlci_data_sweep(dlci->gsm); + } + if (sweep) + gsm_dlci_data_sweep(dlci->gsm); spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags); }
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