[PATCH AUTOSEL 5.4 5/9] ACPI: EC: Fix oops when removing custom query handlers

[Sasha Levin]

From: Armin Wolf <W_Armin@xxxxxx>

[ Upstream commit e5b492c6bb900fcf9722e05f4a10924410e170c1 ]

When removing custom query handlers, the handler might still
be used inside the EC query workqueue, causing a kernel oops
if the module holding the callback function was already unloaded.

Fix this by flushing the EC query workqueue when removing
custom query handlers.

Tested on a Acer Travelmate 4002WLMi

Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/acpi/ec.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index defc5796b5084..c7baccd47b89f 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -1118,6 +1118,7 @@ static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 {
 	acpi_ec_remove_query_handlers(ec, false, query_bit);
+	flush_workqueue(ec_query_wq);
 }
 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 
-- 
2.39.2