From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755442Ab2EUHPE (ORCPT ); Mon, 21 May 2012 03:15:04 -0400 Received: from e28smtp04.in.ibm.com ([122.248.162.4]:60207 "EHLO e28smtp04.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753075Ab2EUHPA (ORCPT ); Mon, 21 May 2012 03:15:00 -0400 From: "Srivatsa S. Bhat" Subject: [PATCH] ftrace: Disable function tracing during suspend/resume and hibernation, again To: rostedt@goodmis.org, rjw@sisk.pl Cc: mingo@kernel.org, lenb@kernel.org, pavel@ucw.cz, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, srivatsa.bhat@linux.vnet.ibm.com Date: Mon, 21 May 2012 12:27:14 +0530 Message-ID: <20120521065651.4142.36898.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit x-cbid: 12052106-5564-0000-0000-000002CBB973 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If function tracing is enabled for some of the low-level suspend/resume functions, it leads to triple fault during resume from suspend, ultimately ending up in a reboot instead of a resume (or a total refusal to come out of suspended state, on some machines). This issue was explained in more detail in commit f42ac38c59e0a03d (ftrace: disable tracing for suspend to ram). However, the changes made by that commit got reverted by commit cbe2f5a6e84eebb (tracing: allow tracing of suspend/resume & hibernation code again). So, unfortunately since things are not yet robust enough to allow tracing of low-level suspend/resume functions, suspend/resume is still broken when ftrace is enabled. So fix this by disabling function tracing during suspend/resume & hibernation. Signed-off-by: Srivatsa S. Bhat Cc: stable@vger.kernel.org --- kernel/power/hibernate.c | 6 ++++++ kernel/power/suspend.c | 3 +++ 2 files changed, 9 insertions(+), 0 deletions(-) diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index e09dfbf..52a1817 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -352,6 +352,7 @@ int hibernation_snapshot(int platform_mode) } suspend_console(); + ftrace_stop(); pm_restrict_gfp_mask(); error = dpm_suspend(PMSG_FREEZE); @@ -377,6 +378,7 @@ int hibernation_snapshot(int platform_mode) if (error || !in_suspend) pm_restore_gfp_mask(); + ftrace_start(); resume_console(); dpm_complete(msg); @@ -479,6 +481,7 @@ int hibernation_restore(int platform_mode) pm_prepare_console(); suspend_console(); + ftrace_stop(); pm_restrict_gfp_mask(); error = dpm_suspend_start(PMSG_QUIESCE); if (!error) { @@ -486,6 +489,7 @@ int hibernation_restore(int platform_mode) dpm_resume_end(PMSG_RECOVER); } pm_restore_gfp_mask(); + ftrace_start(); resume_console(); pm_restore_console(); return error; @@ -512,6 +516,7 @@ int hibernation_platform_enter(void) entering_platform_hibernation = true; suspend_console(); + ftrace_stop(); error = dpm_suspend_start(PMSG_HIBERNATE); if (error) { if (hibernation_ops->recover) @@ -555,6 +560,7 @@ int hibernation_platform_enter(void) Resume_devices: entering_platform_hibernation = false; dpm_resume_end(PMSG_RESTORE); + ftrace_start(); resume_console(); Close: diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 396d262..c8b7446 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include "power.h" @@ -212,6 +213,7 @@ int suspend_devices_and_enter(suspend_state_t state) goto Close; } suspend_console(); + ftrace_stop(); suspend_test_start(); error = dpm_suspend_start(PMSG_SUSPEND); if (error) { @@ -231,6 +233,7 @@ int suspend_devices_and_enter(suspend_state_t state) suspend_test_start(); dpm_resume_end(PMSG_RESUME); suspend_test_finish("resume devices"); + ftrace_start(); resume_console(); Close: if (suspend_ops->end)