Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S948224AbdDTXue (ORCPT ); Thu, 20 Apr 2017 19:50:34 -0400 Received: from mail-io0-f196.google.com ([209.85.223.196]:34473 "EHLO mail-io0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S948209AbdDTXub (ORCPT ); Thu, 20 Apr 2017 19:50:31 -0400 From: Robert Lippert X-Google-Original-From: Robert Lippert To: Corey Minyard Cc: Robert Lippert , openipmi-developer@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: [PATCH] ipmi/watchdog: fix wdog hang on panic waiting for ipmi response Date: Thu, 20 Apr 2017 16:49:47 -0700 Message-Id: <20170420234947.1037-1-rlippert@google.com> X-Mailer: git-send-email 2.12.2.816.g2cccc81164-goog Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1785 Lines: 52 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 --- drivers/char/ipmi/ipmi_watchdog.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/char/ipmi/ipmi_watchdog.c b/drivers/char/ipmi/ipmi_watchdog.c index 5ca24d9b101b..d165af8abe36 100644 --- a/drivers/char/ipmi/ipmi_watchdog.c +++ b/drivers/char/ipmi/ipmi_watchdog.c @@ -516,7 +516,7 @@ static void panic_halt_ipmi_heartbeat(void) 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, @@ -526,7 +526,7 @@ static void panic_halt_ipmi_heartbeat(void) &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 = { @@ -550,12 +550,12 @@ static void panic_halt_ipmi_set_timeout(void) /* 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 { -- 2.12.2.816.g2cccc81164-goog