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=-9.7 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 0740FC54E8E for ; Tue, 12 May 2020 11:53:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D9354206A5 for ; Tue, 12 May 2020 11:53:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729675AbgELLxd (ORCPT ); Tue, 12 May 2020 07:53:33 -0400 Received: from relay2-d.mail.gandi.net ([217.70.183.194]:59057 "EHLO relay2-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729560AbgELLxb (ORCPT ); Tue, 12 May 2020 07:53:31 -0400 X-Originating-IP: 87.231.134.186 Received: from localhost (87-231-134-186.rev.numericable.fr [87.231.134.186]) (Authenticated sender: gregory.clement@bootlin.com) by relay2-d.mail.gandi.net (Postfix) with ESMTPSA id 22C3540010; Tue, 12 May 2020 11:53:30 +0000 (UTC) From: Gregory CLEMENT To: Greg Kroah-Hartman , Jiri Slaby , linux-kernel@vger.kernel.org Cc: Thomas Petazzoni , Gregory CLEMENT Subject: [PATCH v2 2/3] tty: n_gsm: Fix SOF skipping Date: Tue, 12 May 2020 13:53:22 +0200 Message-Id: <20200512115323.1447922-3-gregory.clement@bootlin.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200512115323.1447922-1-gregory.clement@bootlin.com> References: <20200512115323.1447922-1-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 For at least some modems like the TELIT LE910, skipping SOF makes transfers blocking indefinitely after a short amount of data transferred. Given the small improvement provided by skipping the SOF (just one byte on about 100 bytes), it seems better to completely remove this "feature" than make it optional. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Gregory CLEMENT --- drivers/tty/n_gsm.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 67c8f8173023..d8d196645500 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -667,7 +667,6 @@ static void gsm_data_kick(struct gsm_mux *gsm) { struct gsm_msg *msg, *nmsg; int len; - int skip_sof = 0; list_for_each_entry_safe(msg, nmsg, &gsm->tx_list, list) { if (gsm->constipated && msg->addr) @@ -689,15 +688,10 @@ static void gsm_data_kick(struct gsm_mux *gsm) print_hex_dump_bytes("gsm_data_kick: ", DUMP_PREFIX_OFFSET, gsm->txframe, len); - - if (gsm->output(gsm, gsm->txframe + skip_sof, - len - skip_sof) < 0) + if (gsm->output(gsm, gsm->txframe, len) < 0) break; /* FIXME: Can eliminate one SOF in many more cases */ gsm->tx_bytes -= msg->len; - /* For a burst of frames skip the extra SOF within the - burst */ - skip_sof = 1; list_del(&msg->list); kfree(msg); -- 2.26.2