From ad07277e82dedabacc52c82746633680a3187d25 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 20 Aug 2013 01:42:32 +0200 Subject: [PATCH] ACPI / PM: Hold acpi_scan_lock over system PM transitions Bad things happen if ACPI hotplug events are handled during system PM transitions, especially if devices are removed as a result. To prevent those bad things from happening, acquire acpi_scan_lock when a PM transition is started and release it when that transition is complete or has been aborted. This fixes resume lockup on my test-bed Acer Aspire S5 that happens when Thunderbolt devices are disconnected from the machine while suspended. Also fixes the analogous problem for Mika Westerberg on an Intel DZ77RE-75K board. Signed-off-by: Rafael J. Wysocki Tested-by: Mika Westerberg Acked-by: Toshi Kani --- drivers/acpi/sleep.c | 39 ++++++++++++++++++++++++--------------- 1 file changed, 24 insertions(+), 15 deletions(-) diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c index 81b0f03d97db..1dec53decffa 100644 --- a/drivers/acpi/sleep.c +++ b/drivers/acpi/sleep.c @@ -420,10 +420,21 @@ static void acpi_pm_finish(void) } /** - * acpi_pm_end - Finish up suspend sequence. + * acpi_pm_start - Start system PM transition. + */ +static void acpi_pm_start(u32 acpi_state) +{ + acpi_target_sleep_state = acpi_state; + acpi_sleep_tts_switch(acpi_target_sleep_state); + acpi_scan_lock_acquire(); +} + +/** + * acpi_pm_end - Finish up system PM transition. */ static void acpi_pm_end(void) { + acpi_scan_lock_release(); /* * This is necessary in case acpi_pm_finish() is not called during a * failing transition to a sleep state. @@ -451,21 +462,19 @@ static u32 acpi_suspend_states[] = { static int acpi_suspend_begin(suspend_state_t pm_state) { u32 acpi_state = acpi_suspend_states[pm_state]; - int error = 0; + int error; error = (nvs_nosave || nvs_nosave_s3) ? 0 : suspend_nvs_alloc(); if (error) return error; - if (sleep_states[acpi_state]) { - acpi_target_sleep_state = acpi_state; - acpi_sleep_tts_switch(acpi_target_sleep_state); - } else { - printk(KERN_ERR "ACPI does not support this state: %d\n", - pm_state); - error = -ENOSYS; + if (!sleep_states[acpi_state]) { + pr_err("ACPI does not support sleep state S%u\n", acpi_state); + return -ENOSYS; } - return error; + + acpi_pm_start(acpi_state); + return 0; } /** @@ -631,10 +640,8 @@ static int acpi_hibernation_begin(void) int error; error = nvs_nosave ? 0 : suspend_nvs_alloc(); - if (!error) { - acpi_target_sleep_state = ACPI_STATE_S4; - acpi_sleep_tts_switch(acpi_target_sleep_state); - } + if (!error) + acpi_pm_start(ACPI_STATE_S4); return error; } @@ -713,8 +720,10 @@ static int acpi_hibernation_begin_old(void) if (!error) { if (!nvs_nosave) error = suspend_nvs_alloc(); - if (!error) + if (!error) { acpi_target_sleep_state = ACPI_STATE_S4; + acpi_scan_lock_acquire(); + } } return error; } -- 2.30.2