From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752523AbbALSFX (ORCPT ); Mon, 12 Jan 2015 13:05:23 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:57280 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752180AbbALSFU (ORCPT ); Mon, 12 Jan 2015 13:05:20 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Martin Schwidefsky , Ben Hutchings , Luis Henriques Subject: [PATCH 3.16.y-ckt 004/216] s390/3215: fix hanging console issue Date: Mon, 12 Jan 2015 18:02:01 +0000 Message-Id: <1421085933-32536-5-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1421085933-32536-1-git-send-email-luis.henriques@canonical.com> References: <1421085933-32536-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.7-ckt4 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Martin Schwidefsky commit 26d766c60f4ea08cd14f0f3435a6db3d6cc2ae96 upstream. The ccw_device_start in raw3215_start_io can fail. raw3215_try_io does not check if the request could be started and removes any pending timer. This can leave the system in a hanging state. Check for pending request after raw3215_start_io and start a timer if necessary. Signed-off-by: Martin Schwidefsky Cc: Ben Hutchings Signed-off-by: Luis Henriques --- drivers/s390/char/con3215.c | 32 +++++++++++++++++--------------- 1 file changed, 17 insertions(+), 15 deletions(-) diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c index 5af7f0bd6125..a6d47e5eee9e 100644 --- a/drivers/s390/char/con3215.c +++ b/drivers/s390/char/con3215.c @@ -288,12 +288,16 @@ static void raw3215_timeout(unsigned long __data) unsigned long flags; spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags); - if (raw->flags & RAW3215_TIMER_RUNS) { - del_timer(&raw->timer); - raw->flags &= ~RAW3215_TIMER_RUNS; - if (!(raw->port.flags & ASYNC_SUSPENDED)) { - raw3215_mk_write_req(raw); - raw3215_start_io(raw); + raw->flags &= ~RAW3215_TIMER_RUNS; + if (!(raw->port.flags & ASYNC_SUSPENDED)) { + raw3215_mk_write_req(raw); + raw3215_start_io(raw); + if ((raw->queued_read || raw->queued_write) && + !(raw->flags & RAW3215_WORKING) && + !(raw->flags & RAW3215_TIMER_RUNS)) { + raw->timer.expires = RAW3215_TIMEOUT + jiffies; + add_timer(&raw->timer); + raw->flags |= RAW3215_TIMER_RUNS; } } spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags); @@ -317,17 +321,15 @@ static inline void raw3215_try_io(struct raw3215_info *raw) (raw->flags & RAW3215_FLUSHING)) { /* execute write requests bigger than minimum size */ raw3215_start_io(raw); - if (raw->flags & RAW3215_TIMER_RUNS) { - del_timer(&raw->timer); - raw->flags &= ~RAW3215_TIMER_RUNS; - } - } else if (!(raw->flags & RAW3215_TIMER_RUNS)) { - /* delay small writes */ - raw->timer.expires = RAW3215_TIMEOUT + jiffies; - add_timer(&raw->timer); - raw->flags |= RAW3215_TIMER_RUNS; } } + if ((raw->queued_read || raw->queued_write) && + !(raw->flags & RAW3215_WORKING) && + !(raw->flags & RAW3215_TIMER_RUNS)) { + raw->timer.expires = RAW3215_TIMEOUT + jiffies; + add_timer(&raw->timer); + raw->flags |= RAW3215_TIMER_RUNS; + } } /* -- 2.1.4