216 lines
6.6 KiB
Diff
216 lines
6.6 KiB
Diff
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From: Rafael J. Wysocki <rjw@sisk.pl>
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Date: Thu, 8 Apr 2010 23:39:40 +0000 (+0200)
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Subject: ACPI / EC / PM: Fix race between EC transactions and system suspend
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X-Git-Tag: v2.6.35-rc2~39^2~3
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X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=d5a64513c6a171262082c250592c062e97a2c693
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ACPI / EC / PM: Fix race between EC transactions and system suspend
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There still is a race that may result in suspending the system in
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the middle of an EC transaction in progress, which leads to problems
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(like the kernel thinking that the ACPI global lock is held during
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resume while in fact it's not).
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To remove the race condition, modify the ACPI platform suspend and
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hibernate callbacks so that EC transactions are blocked right after
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executing the _PTS global control method and are allowed to happen
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again right after the low-level wakeup.
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Introduce acpi_pm_freeze() that will disable GPEs, wait until the
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event queues are empty and block EC transactions. Use it wherever
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GPEs are disabled in preparation for switching local interrupts off.
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Introduce acpi_pm_thaw() that will allow EC transactions to happen
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again and enable runtime GPEs. Use it to balance acpi_pm_freeze()
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wherever necessary.
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In addition to that use acpi_ec_resume_transactions_early() to
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unblock EC transactions as early as reasonably possible during
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resume. Also unblock EC transactions in acpi_hibernation_finish()
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and in the analogous suspend routine to make sure that the EC
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transactions are enabled in all error paths.
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Fixes https://bugzilla.kernel.org/show_bug.cgi?id=14668
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Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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Reported-and-tested-by: Maxim Levitsky <maximlevitsky@gmail.com>
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Signed-off-by: Len Brown <len.brown@intel.com>
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---
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diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
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index f2234db..2c2b73a 100644
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--- a/drivers/acpi/ec.c
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+++ b/drivers/acpi/ec.c
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@@ -485,6 +485,16 @@ void acpi_ec_resume_transactions(void)
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mutex_unlock(&ec->lock);
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}
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+void acpi_ec_resume_transactions_early(void)
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+{
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+ /*
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+ * Allow transactions to happen again (this function is called from
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+ * atomic context during wakeup, so we don't need to acquire the mutex).
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+ */
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+ if (first_ec)
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+ clear_bit(EC_FLAGS_FROZEN, &first_ec->flags);
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+}
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+
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static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
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{
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int result;
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diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
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index e284113..0ec48c7 100644
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--- a/drivers/acpi/internal.h
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+++ b/drivers/acpi/internal.h
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@@ -51,6 +51,7 @@ int acpi_ec_ecdt_probe(void);
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int acpi_boot_ec_enable(void);
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void acpi_ec_suspend_transactions(void);
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void acpi_ec_resume_transactions(void);
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+void acpi_ec_resume_transactions_early(void);
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/*--------------------------------------------------------------------------
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Suspend/Resume
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diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
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index baa76bb..24741ac 100644
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--- a/drivers/acpi/sleep.c
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+++ b/drivers/acpi/sleep.c
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@@ -110,11 +110,13 @@ void __init acpi_old_suspend_ordering(void)
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}
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/**
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- * acpi_pm_disable_gpes - Disable the GPEs.
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+ * acpi_pm_freeze - Disable the GPEs and suspend EC transactions.
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*/
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-static int acpi_pm_disable_gpes(void)
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+static int acpi_pm_freeze(void)
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{
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acpi_disable_all_gpes();
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+ acpi_os_wait_events_complete(NULL);
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+ acpi_ec_suspend_transactions();
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return 0;
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}
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@@ -142,7 +144,8 @@ static int acpi_pm_prepare(void)
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int error = __acpi_pm_prepare();
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if (!error)
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- acpi_disable_all_gpes();
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+ acpi_pm_freeze();
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+
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return error;
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}
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@@ -275,6 +278,8 @@ static int acpi_suspend_enter(suspend_state_t pm_state)
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* acpi_leave_sleep_state will reenable specific GPEs later
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*/
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acpi_disable_all_gpes();
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+ /* Allow EC transactions to happen. */
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+ acpi_ec_resume_transactions_early();
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local_irq_restore(flags);
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printk(KERN_DEBUG "Back to C!\n");
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@@ -286,6 +291,12 @@ static int acpi_suspend_enter(suspend_state_t pm_state)
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return ACPI_SUCCESS(status) ? 0 : -EFAULT;
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}
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+static void acpi_suspend_finish(void)
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+{
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+ acpi_ec_resume_transactions();
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+ acpi_pm_finish();
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+}
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+
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static int acpi_suspend_state_valid(suspend_state_t pm_state)
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{
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u32 acpi_state;
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@@ -307,7 +318,7 @@ static struct platform_suspend_ops acpi_suspend_ops = {
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.begin = acpi_suspend_begin,
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.prepare_late = acpi_pm_prepare,
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.enter = acpi_suspend_enter,
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- .wake = acpi_pm_finish,
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+ .wake = acpi_suspend_finish,
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.end = acpi_pm_end,
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};
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@@ -333,9 +344,9 @@ static int acpi_suspend_begin_old(suspend_state_t pm_state)
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static struct platform_suspend_ops acpi_suspend_ops_old = {
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.valid = acpi_suspend_state_valid,
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.begin = acpi_suspend_begin_old,
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- .prepare_late = acpi_pm_disable_gpes,
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+ .prepare_late = acpi_pm_freeze,
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.enter = acpi_suspend_enter,
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- .wake = acpi_pm_finish,
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+ .wake = acpi_suspend_finish,
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.end = acpi_pm_end,
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.recover = acpi_pm_finish,
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};
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@@ -586,6 +597,7 @@ static int acpi_hibernation_enter(void)
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static void acpi_hibernation_finish(void)
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{
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hibernate_nvs_free();
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+ acpi_ec_resume_transactions();
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acpi_pm_finish();
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}
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@@ -606,17 +618,11 @@ static void acpi_hibernation_leave(void)
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}
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/* Restore the NVS memory area */
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hibernate_nvs_restore();
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+ /* Allow EC transactions to happen. */
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+ acpi_ec_resume_transactions_early();
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}
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-static int acpi_pm_pre_restore(void)
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-{
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- acpi_disable_all_gpes();
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- acpi_os_wait_events_complete(NULL);
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- acpi_ec_suspend_transactions();
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- return 0;
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-}
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-
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-static void acpi_pm_restore_cleanup(void)
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+static void acpi_pm_thaw(void)
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{
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acpi_ec_resume_transactions();
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acpi_enable_all_runtime_gpes();
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@@ -630,8 +636,8 @@ static struct platform_hibernation_ops acpi_hibernation_ops = {
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.prepare = acpi_pm_prepare,
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.enter = acpi_hibernation_enter,
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.leave = acpi_hibernation_leave,
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- .pre_restore = acpi_pm_pre_restore,
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- .restore_cleanup = acpi_pm_restore_cleanup,
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+ .pre_restore = acpi_pm_freeze,
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+ .restore_cleanup = acpi_pm_thaw,
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};
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/**
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@@ -663,12 +669,9 @@ static int acpi_hibernation_begin_old(void)
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static int acpi_hibernation_pre_snapshot_old(void)
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{
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- int error = acpi_pm_disable_gpes();
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-
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- if (!error)
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- hibernate_nvs_save();
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-
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- return error;
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+ acpi_pm_freeze();
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+ hibernate_nvs_save();
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+ return 0;
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}
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/*
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@@ -680,11 +683,11 @@ static struct platform_hibernation_ops acpi_hibernation_ops_old = {
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.end = acpi_pm_end,
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.pre_snapshot = acpi_hibernation_pre_snapshot_old,
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.finish = acpi_hibernation_finish,
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- .prepare = acpi_pm_disable_gpes,
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+ .prepare = acpi_pm_freeze,
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.enter = acpi_hibernation_enter,
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.leave = acpi_hibernation_leave,
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- .pre_restore = acpi_pm_pre_restore,
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- .restore_cleanup = acpi_pm_restore_cleanup,
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+ .pre_restore = acpi_pm_freeze,
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+ .restore_cleanup = acpi_pm_thaw,
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.recover = acpi_pm_finish,
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};
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#endif /* CONFIG_HIBERNATION */
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