From patchwork Mon Dec 28 12:49:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 354244 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 3ECCCC43332 for ; Mon, 28 Dec 2020 16:44:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 06E472245C for ; Mon, 28 Dec 2020 16:44:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728938AbgL1M5Q (ORCPT ); Mon, 28 Dec 2020 07:57:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:53436 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728936AbgL1M5Q (ORCPT ); Mon, 28 Dec 2020 07:57:16 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4FE93229C6; Mon, 28 Dec 2020 12:57:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609160220; bh=WxAUeKSKOvzBCHMhXnRw11xywl3lvvwy8E/MCivO0EQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yKrzjQN0Avva92je7x4bca0vjANqgaGDboHz1Ki+rhgTArIdf7/cknJdbrBWn6gtH SPS1cVYXwFSMLTyeTzz04IuyOqMVZ1kUymXH9zGXLhu5i8HTcDsvAIMr1zbWOTPzj+ hgjaFSt5KZFEdXNwAc40EypC5ZVeQZWNTxJdNdBI= 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 4.4 109/132] USB: serial: keyspan_pda: fix dropped unthrottle interrupts Date: Mon, 28 Dec 2020 13:49:53 +0100 Message-Id: <20201228124851.682215879@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228124846.409999325@linuxfoundation.org> References: <20201228124846.409999325@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;