platform/x86: wmi: Replace read_takes_no_args with a flags field

Replace the wmi_block.read_takes_no_args bool field with
an unsigned long flags field, used together with test_bit()
and friends.

This is a preparation patch for fixing a driver->notify() vs ->probe()
race, which requires atomic flag handling.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20211128190031.405620-1-hdegoede@redhat.com

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index c34341f4da763381643cafafb4f144521e8bae34..46178e03aecadbd9293a8e32dd6adb024026c149 100644 (file)
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -57,6 +57,10 @@ static_assert(sizeof(typeof_member(struct guid_block, guid)) == 16);
 static_assert(sizeof(struct guid_block) == 20);
 static_assert(__alignof__(struct guid_block) == 1);
 
+enum { /* wmi_block flags */
+       WMI_READ_TAKES_NO_ARGS,
+};
+
 struct wmi_block {
        struct wmi_device dev;
        struct list_head list;
@@ -67,8 +71,7 @@ struct wmi_block {
        wmi_notify_handler handler;
        void *handler_data;
        u64 req_buf_size;
-
-       bool read_takes_no_args;
+       unsigned long flags;
 };
 
 
@@ -367,7 +370,7 @@ static acpi_status __query_block(struct wmi_block *wblock, u8 instance,
        wq_params[0].type = ACPI_TYPE_INTEGER;
        wq_params[0].integer.value = instance;
 
-       if (instance == 0 && wblock->read_takes_no_args)
+       if (instance == 0 && test_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags))
                input.count = 0;
 
        /*
@@ -1113,7 +1116,7 @@ static int wmi_create_device(struct device *wmi_bus_dev,
         * laptops, WQxx may not be a method at all.)
         */
        if (info->type != ACPI_TYPE_METHOD || info->param_count == 0)
-               wblock->read_takes_no_args = true;
+               set_bit(WMI_READ_TAKES_NO_ARGS, &wblock->flags);
 
        kfree(info);