From patchwork Mon Dec 28 12:49:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 354301 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 3A962C433E0 for ; Mon, 28 Dec 2020 16:31:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 13244208D5 for ; Mon, 28 Dec 2020 16:31:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730574AbgL1QbR (ORCPT ); Mon, 28 Dec 2020 11:31:17 -0500 Received: from mail.kernel.org ([198.145.29.99]:32854 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730621AbgL1NF3 (ORCPT ); Mon, 28 Dec 2020 08:05:29 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 132712242A; Mon, 28 Dec 2020 13:05:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609160713; bh=WxAUeKSKOvzBCHMhXnRw11xywl3lvvwy8E/MCivO0EQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AdvMOJOII3IwxwcP2djiIA41j1jfMUnn4BPr31CzwLz4OTqjLu3vri7zM2fnpvtLc 8juLtLvN5vv4Bk9IVRqFHqHE7bb38YCE1n+l7FZu9gJF8nEullIfO5p6sQMTcL+7A0 8GRRYB8v8i5mL6FpNzPXnN1wvWrATNEfj57may1E= 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 4.9 145/175] USB: serial: keyspan_pda: fix dropped unthrottle interrupts Date: Mon, 28 Dec 2020 13:49:58 +0100 Message-Id: <20201228124900.276232789@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228124853.216621466@linuxfoundation.org> References: <20201228124853.216621466@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 @@ -176,11 +176,11 @@ 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;