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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 A3A38C83004 for ; Tue, 28 Apr 2020 18:37:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7E18820B80 for ; Tue, 28 Apr 2020 18:37:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588099029; bh=vPgXxGI66rLRdoSQpuNxxGXdIZQViP/JDAYkzmrJUQ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=WrFyuHo2LLix8oM+qQDn7AZ5a6w95WX+pzPewNfarbSBGYedVtQmw6D8GJswJYnHO 7Mz720EKOqyzt++AoL7HmeWFnFeib6vxPZrm6RCwx1B2hTESTuIYynk2VkkryX52pB 0+L6M4thl4SrXy5JEMciqDAw5wZdYdM5Paq12wrk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730446AbgD1ShI (ORCPT ); Tue, 28 Apr 2020 14:37:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:54850 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730433AbgD1ShE (ORCPT ); Tue, 28 Apr 2020 14:37:04 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3DF5720730; Tue, 28 Apr 2020 18:37:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588099023; bh=vPgXxGI66rLRdoSQpuNxxGXdIZQViP/JDAYkzmrJUQ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o5t7pMg/vOubNwXfrouG+CmOwrkphAfAwJYIP3bCJ5k8/0g/ePgv1zCX/iy6ErcUf 9EIOlEe+vQmepMGI+VDRA2y3zahuToXWSXJs4ubP6sBQZ7tsZr9E5vM+c8qO67em9D YLK1gRayh3CEMznv80L/Z7M8Yz9LtfJ6zOffBqdM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Oliver Neukum , Jonas Karlsson Subject: [PATCH 5.6 145/167] cdc-acm: introduce a cool down Date: Tue, 28 Apr 2020 20:25:21 +0200 Message-Id: <20200428182243.941621809@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200428182225.451225420@linuxfoundation.org> References: <20200428182225.451225420@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Oliver Neukum commit a4e7279cd1d19f48f0af2a10ed020febaa9ac092 upstream. Immediate submission in case of a babbling device can lead to a busy loop. Introducing a delayed work. Signed-off-by: Oliver Neukum Cc: stable Tested-by: Jonas Karlsson Link: https://lore.kernel.org/r/20200415151358.32664-2-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/class/cdc-acm.c | 30 ++++++++++++++++++++++++++++-- drivers/usb/class/cdc-acm.h | 5 ++++- 2 files changed, 32 insertions(+), 3 deletions(-) --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -412,9 +412,12 @@ static void acm_ctrl_irq(struct urb *urb exit: retval = usb_submit_urb(urb, GFP_ATOMIC); - if (retval && retval != -EPERM) + if (retval && retval != -EPERM && retval != -ENODEV) dev_err(&acm->control->dev, "%s - usb_submit_urb failed: %d\n", __func__, retval); + else + dev_vdbg(&acm->control->dev, + "control resubmission terminated %d\n", retval); } static int acm_submit_read_urb(struct acm *acm, int index, gfp_t mem_flags) @@ -430,6 +433,8 @@ static int acm_submit_read_urb(struct ac dev_err(&acm->data->dev, "urb %d failed submission with %d\n", index, res); + } else { + dev_vdbg(&acm->data->dev, "intended failure %d\n", res); } set_bit(index, &acm->read_urbs_free); return res; @@ -471,6 +476,7 @@ static void acm_read_bulk_callback(struc int status = urb->status; bool stopped = false; bool stalled = false; + bool cooldown = false; dev_vdbg(&acm->data->dev, "got urb %d, len %d, status %d\n", rb->index, urb->actual_length, status); @@ -497,6 +503,14 @@ static void acm_read_bulk_callback(struc __func__, status); stopped = true; break; + case -EOVERFLOW: + case -EPROTO: + dev_dbg(&acm->data->dev, + "%s - cooling babbling device\n", __func__); + usb_mark_last_busy(acm->dev); + set_bit(rb->index, &acm->urbs_in_error_delay); + cooldown = true; + break; default: dev_dbg(&acm->data->dev, "%s - nonzero urb status received: %d\n", @@ -518,9 +532,11 @@ static void acm_read_bulk_callback(struc */ smp_mb__after_atomic(); - if (stopped || stalled) { + if (stopped || stalled || cooldown) { if (stalled) schedule_work(&acm->work); + else if (cooldown) + schedule_delayed_work(&acm->dwork, HZ / 2); return; } @@ -567,6 +583,12 @@ static void acm_softint(struct work_stru } } + if (test_and_clear_bit(ACM_ERROR_DELAY, &acm->flags)) { + for (i = 0; i < ACM_NR; i++) + if (test_and_clear_bit(i, &acm->urbs_in_error_delay)) + acm_submit_read_urb(acm, i, GFP_NOIO); + } + if (test_and_clear_bit(EVENT_TTY_WAKEUP, &acm->flags)) tty_port_tty_wakeup(&acm->port); } @@ -1333,6 +1355,7 @@ made_compressed_probe: acm->readsize = readsize; acm->rx_buflimit = num_rx_buf; INIT_WORK(&acm->work, acm_softint); + INIT_DELAYED_WORK(&acm->dwork, acm_softint); init_waitqueue_head(&acm->wioctl); spin_lock_init(&acm->write_lock); spin_lock_init(&acm->read_lock); @@ -1542,6 +1565,7 @@ static void acm_disconnect(struct usb_in acm_kill_urbs(acm); cancel_work_sync(&acm->work); + cancel_delayed_work_sync(&acm->dwork); tty_unregister_device(acm_tty_driver, acm->minor); @@ -1584,6 +1608,8 @@ static int acm_suspend(struct usb_interf acm_kill_urbs(acm); cancel_work_sync(&acm->work); + cancel_delayed_work_sync(&acm->dwork); + acm->urbs_in_error_delay = 0; return 0; } --- a/drivers/usb/class/cdc-acm.h +++ b/drivers/usb/class/cdc-acm.h @@ -109,8 +109,11 @@ struct acm { # define EVENT_TTY_WAKEUP 0 # define EVENT_RX_STALL 1 # define ACM_THROTTLED 2 +# define ACM_ERROR_DELAY 3 + unsigned long urbs_in_error_delay; /* these need to be restarted after a delay */ struct usb_cdc_line_coding line; /* bits, stop, parity */ - struct work_struct work; /* work queue entry for line discipline waking up */ + struct work_struct work; /* work queue entry for various purposes*/ + struct delayed_work dwork; /* for cool downs needed in error recovery */ unsigned int ctrlin; /* input control lines (DCD, DSR, RI, break, overruns) */ unsigned int ctrlout; /* output control lines (DTR, RTS) */ struct async_icount iocount; /* counters for control line changes */