From patchwork Mon Dec 28 12:50:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 353199 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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_RED, USER_AGENT_GIT autolearn=unavailable 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 E4DD3C43381 for ; Mon, 28 Dec 2020 15:56:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9FC2A206E5 for ; Mon, 28 Dec 2020 15:56:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389316AbgL1NfU (ORCPT ); Mon, 28 Dec 2020 08:35:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:35420 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389320AbgL1NfT (ORCPT ); Mon, 28 Dec 2020 08:35:19 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id E6477207C9; Mon, 28 Dec 2020 13:35:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609162503; bh=7cQDaEUqqy2Z+ZsG1YF2Up5+GInOJP/+GzQEoaKyGPM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=n+SQjiZhubjptwgoDxg/EqHl4TIIzSLcS8RSZiufpXfgsomRmhqrhOrUvxspAv0fL 2uVbnWoNcb91uG4HNQxZ5wcDz5MJV6MekPy2I/DrqdavED2UQ9czOLis9Z9GJtHsPl IkJJUH5bgaFvghuXkV6CO2s8ys/VcJttpWCjj/eg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sebastian Andrzej Siewior , Johan Hovold Subject: [PATCH 4.19 291/346] USB: serial: keyspan_pda: fix dropped unthrottle interrupts Date: Mon, 28 Dec 2020 13:50:10 +0100 Message-Id: <20201228124933.844993053@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228124919.745526410@linuxfoundation.org> References: <20201228124919.745526410@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Johan Hovold commit 696c541c8c6cfa05d65aa24ae2b9e720fc01766e upstream. Commit c528fcb116e6 ("USB: serial: keyspan_pda: fix receive sanity checks") broke write-unthrottle handling by dropping well-formed unthrottle-interrupt packets which are precisely two bytes long. This could lead to blocked writers not being woken up when buffer space again becomes available. Instead, stop unconditionally printing the third byte which is (presumably) only valid on modem-line changes. Fixes: c528fcb116e6 ("USB: serial: keyspan_pda: fix receive sanity checks") Cc: stable # 4.11 Acked-by: Sebastian Andrzej Siewior Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/keyspan_pda.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/usb/serial/keyspan_pda.c +++ b/drivers/usb/serial/keyspan_pda.c @@ -172,11 +172,11 @@ static void keyspan_pda_rx_interrupt(str break; case 1: /* status interrupt */ - if (len < 3) { + if (len < 2) { dev_warn(&port->dev, "short interrupt message received\n"); break; } - dev_dbg(&port->dev, "rx int, d1=%d, d2=%d\n", data[1], data[2]); + dev_dbg(&port->dev, "rx int, d1=%d\n", data[1]); switch (data[1]) { case 1: /* modemline change */ break;