[PATCH v4 3/7] ACPI: button: Access input device's users under appropriate mutex

[Andrzej Pietrasiewicz]

Inspecting input device's 'users' member should be done under device's
mutex, so add appropriate invocations.

Signed-off-by: Andrzej Pietrasiewicz <andrze...@collabora.com>
---
 drivers/acpi/button.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index 78cfc70cb320..ff7ab291f678 100644
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -456,13 +456,16 @@ static int acpi_button_resume(struct device *dev)
 {
        struct acpi_device *device = to_acpi_device(dev);
        struct acpi_button *button = acpi_driver_data(device);
+       struct input_dev *input = button->input;
 
        button->suspended = false;
-       if (button->type == ACPI_BUTTON_TYPE_LID && button->input->users) {
+       mutex_lock(&input->mutex);
+       if (button->type == ACPI_BUTTON_TYPE_LID && input->users) {
                button->last_state = !!acpi_lid_evaluate_state(device);
                button->last_time = ktime_get();
                acpi_lid_initialize_state(device);
        }
+       mutex_unlock(&input->mutex);
        return 0;
 }
 #endif
-- 
2.17.1