From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933967Ab2JDVWa (ORCPT ); Thu, 4 Oct 2012 17:22:30 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:45178 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933928Ab2JDVWT (ORCPT ); Thu, 4 Oct 2012 17:22:19 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Russ Gorby , "Kappel, LaurentX" , Alan Cox Subject: [ 41/58] n_gsm: uplink SKBs accumulate on list Date: Thu, 4 Oct 2012 14:19:48 -0700 Message-Id: <20121004210640.604690654@linuxfoundation.org> X-Mailer: git-send-email 1.7.12.2.421.g261b511 In-Reply-To: <20121004210635.449598766@linuxfoundation.org> References: <20121004210635.449598766@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Russ Gorby 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 Tested-by: Kappel, LaurentX Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- 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); }