From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6C108C433DF for ; Mon, 18 May 2020 08:46:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 483EB20787 for ; Mon, 18 May 2020 08:46:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727917AbgERIqF (ORCPT ); Mon, 18 May 2020 04:46:05 -0400 Received: from relay1-d.mail.gandi.net ([217.70.183.193]:45729 "EHLO relay1-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727827AbgERIqB (ORCPT ); Mon, 18 May 2020 04:46:01 -0400 X-Originating-IP: 91.175.115.186 Received: from localhost (91-175-115-186.subs.proxad.net [91.175.115.186]) (Authenticated sender: gregory.clement@bootlin.com) by relay1-d.mail.gandi.net (Postfix) with ESMTPSA id 19028240017; Mon, 18 May 2020 08:45:59 +0000 (UTC) From: Gregory CLEMENT To: Greg Kroah-Hartman , Jiri Slaby , linux-kernel@vger.kernel.org Cc: Thomas Petazzoni , Gregory CLEMENT Subject: [PATCH v2 3/3] tty: n_gsm: Fix waking up upper tty layer when room available Date: Mon, 18 May 2020 10:45:17 +0200 Message-Id: <20200518084517.2173242-7-gregory.clement@bootlin.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200518084517.2173242-1-gregory.clement@bootlin.com> References: <20200518084517.2173242-1-gregory.clement@bootlin.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Warn the upper layer when n_gms is ready to receive data again. Without this the associated virtual tty remains blocked indefinitely. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Gregory CLEMENT --- drivers/tty/n_gsm.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index d8d196645500..69200bd411f7 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -663,7 +663,7 @@ static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len, * FIXME: lock against link layer control transmissions */ -static void gsm_data_kick(struct gsm_mux *gsm) +static void gsm_data_kick(struct gsm_mux *gsm, struct gsm_dlci *dlci) { struct gsm_msg *msg, *nmsg; int len; @@ -695,6 +695,24 @@ static void gsm_data_kick(struct gsm_mux *gsm) list_del(&msg->list); kfree(msg); + + if (dlci) { + tty_port_tty_wakeup(&dlci->port); + } else { + int i = 0; + + for (i = 0; i < NUM_DLCI; i++) { + struct gsm_dlci *dlci; + + dlci = gsm->dlci[i]; + if (dlci == NULL) { + i++; + continue; + } + + tty_port_tty_wakeup(&dlci->port); + } + } } } @@ -746,7 +764,7 @@ static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg) /* Add to the actual output queue */ list_add_tail(&msg->list, &gsm->tx_list); gsm->tx_bytes += msg->len; - gsm_data_kick(gsm); + gsm_data_kick(gsm, dlci); } /** @@ -1207,7 +1225,7 @@ static void gsm_control_message(struct gsm_mux *gsm, unsigned int command, gsm_control_reply(gsm, CMD_FCON, NULL, 0); /* Kick the link in case it is idling */ spin_lock_irqsave(&gsm->tx_lock, flags); - gsm_data_kick(gsm); + gsm_data_kick(gsm, NULL); spin_unlock_irqrestore(&gsm->tx_lock, flags); break; case CMD_FCOFF: @@ -2529,7 +2547,7 @@ static void gsmld_write_wakeup(struct tty_struct *tty) /* Queue poll */ clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); spin_lock_irqsave(&gsm->tx_lock, flags); - gsm_data_kick(gsm); + gsm_data_kick(gsm, NULL); if (gsm->tx_bytes < TX_THRESH_LO) { gsm_dlci_data_sweep(gsm); } -- 2.26.2