From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:46556 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933234AbeCWKQB (ORCPT ); Fri, 23 Mar 2018 06:16:01 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Robert Lippert , Corey Minyard , Sasha Levin Subject: [PATCH 4.4 57/97] ipmi/watchdog: fix wdog hang on panic waiting for ipmi response Date: Fri, 23 Mar 2018 10:54:44 +0100 Message-Id: <20180323094200.838250542@linuxfoundation.org> In-Reply-To: <20180323094157.535925724@linuxfoundation.org> References: <20180323094157.535925724@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Robert Lippert [ Upstream commit 2c1175c2e8e5487233cabde358a19577562ac83e ] Commit c49c097610fe ("ipmi: Don't call receive handler in the panic context") means that the panic_recv_free is not called during a panic and the atomic count does not drop to 0. Fix this by only expecting one decrement of the atomic variable which comes from panic_smi_free. Signed-off-by: Robert Lippert Signed-off-by: Corey Minyard Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/char/ipmi/ipmi_watchdog.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/drivers/char/ipmi/ipmi_watchdog.c +++ b/drivers/char/ipmi/ipmi_watchdog.c @@ -515,7 +515,7 @@ static void panic_halt_ipmi_heartbeat(vo msg.cmd = IPMI_WDOG_RESET_TIMER; msg.data = NULL; msg.data_len = 0; - atomic_add(2, &panic_done_count); + atomic_add(1, &panic_done_count); rv = ipmi_request_supply_msgs(watchdog_user, (struct ipmi_addr *) &addr, 0, @@ -525,7 +525,7 @@ static void panic_halt_ipmi_heartbeat(vo &panic_halt_heartbeat_recv_msg, 1); if (rv) - atomic_sub(2, &panic_done_count); + atomic_sub(1, &panic_done_count); } static struct ipmi_smi_msg panic_halt_smi_msg = { @@ -549,12 +549,12 @@ static void panic_halt_ipmi_set_timeout( /* Wait for the messages to be free. */ while (atomic_read(&panic_done_count) != 0) ipmi_poll_interface(watchdog_user); - atomic_add(2, &panic_done_count); + atomic_add(1, &panic_done_count); rv = i_ipmi_set_timeout(&panic_halt_smi_msg, &panic_halt_recv_msg, &send_heartbeat_now); if (rv) { - atomic_sub(2, &panic_done_count); + atomic_sub(1, &panic_done_count); printk(KERN_WARNING PFX "Unable to extend the watchdog timeout."); } else {