[PATCH 5.15 041/230] platform/x86: wmi: Replace read_takes_no_args with a flags field

Greg Kroah-Hartman
2022-07-11T09:42:33Z

From: Hans de Goede <hdegoede@redhat.com>

[ Upstream commit a90b38c58667142ecff2521481ed44286d46b140 ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/platform/x86/wmi.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 9aeb1a009097..a00b72ace6d2 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -51,6 +51,10 @@ struct guid_block {
u8 flags;
};

+enum { /* wmi_block flags */
+ WMI_READ_TAKES_NO_ARGS,
+};
+
struct wmi_block {
struct wmi_device dev;
struct list_head list;
@@ -61,8 +65,7 @@ struct wmi_block {
wmi_notify_handler handler;
void *handler_data;
u64 req_buf_size;
-
- bool read_takes_no_args;
+ unsigned long flags;
};

@@ -325,7 +328,7 @@ 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;

/*
@@ -1087,7 +1090,7 @@ 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);

--
2.35.1