[PATCH] PM: suspend: Fix platform_suspend_prepare_noirq()

From: Rafael J. Wysocki
Date: Sat Aug 10 2019 - 07:24:39 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

After commit ac9eafbe930a ("ACPI: PM: s2idle: Execute LPS0 _DSM
functions with suspended devices"), a NULL pointer may be dereferenced
if suspend-to-idle is attempted on a platform without "traditional"
suspend support due to invalid fall-through in
platform_suspend_prepare_noirq().

Fix that and while at it add missing braces in platform_resume_noirq().

Fixes: ac9eafbe930a ("ACPI: PM: s2idle: Execute LPS0 _DSM functions with suspended devices")
Reported-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---

Commit ac9eafbe930a is in linux-next only at this point.

---
kernel/power/suspend.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

Index: linux-pm/kernel/power/suspend.c
===================================================================
--- linux-pm.orig/kernel/power/suspend.c
+++ linux-pm/kernel/power/suspend.c
@@ -253,10 +253,10 @@ static int platform_suspend_prepare_late

static int platform_suspend_prepare_noirq(suspend_state_t state)
{
- if (state == PM_SUSPEND_TO_IDLE) {
- if (s2idle_ops && s2idle_ops->prepare_late)
- return s2idle_ops->prepare_late();
- }
+ if (state == PM_SUSPEND_TO_IDLE)
+ return s2idle_ops && s2idle_ops->prepare_late ?
+ s2idle_ops->prepare_late() : 0;
+
return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0;
}

@@ -265,8 +265,9 @@ static void platform_resume_noirq(suspen
if (state == PM_SUSPEND_TO_IDLE) {
if (s2idle_ops && s2idle_ops->restore_early)
s2idle_ops->restore_early();
- } else if (suspend_ops->wake)
+ } else if (suspend_ops->wake) {
suspend_ops->wake();
+ }
}

static void platform_resume_early(suspend_state_t state)