Commit 192b6041 authored Aug 13, 2012 by Russ Gorby Committed by Greg Kroah-Hartman Aug 16, 2012

n_gsm: uplink SKBs accumulate on list



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>
Cc: Hay and Water <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 7e8ac7b2

drivers/tty/n_gsm.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -971,15 +971,18 @@ static void gsm_dlci_data_sweep(struct gsm_mux *gsm)
		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)
		}
		if (sweep)
		gsm_dlci_data_sweep(dlci->gsm);
		spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);
		}