[RFC PATCH] ACPI / EC: Fix an order issue in ec_remove_handlers()

From: Lv Zheng
Date: Wed Jul 06 2016 - 21:53:14 EST


There is an order issue in ec_remove_handlers() that the functions invoked
in it are not invoked in the reversed order of their appearance in
ec_install_handlers(). This existing issue has been triggered by the
following commit:
Commit: dcf15cbded656a12335bc4151f3f75f10080a375
Subject: ACPI / EC: Fix a boot EC regresion by restoring boot EC
The commit invokes ec_remove_handlers() during runtime, thus uncovers this
issue. This patch fixes this regression.

Fixes: dcf15cbded65 ("ACPI / EC: Fix a boot EC regresion by restoring boot EC")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=102421
Reported-by: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Reported-by: Nicholas <nkudriavtsev@xxxxxxxxx>
Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Cc: Nicholas <nkudriavtsev@xxxxxxxxx>
Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
---
drivers/acpi/ec.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index b1050a0..9ff3d4b 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -1331,7 +1331,12 @@ static int ec_install_handlers(struct acpi_ec *ec)

static void ec_remove_handlers(struct acpi_ec *ec)
{
- acpi_ec_stop(ec, false);
+ if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
+ if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
+ &acpi_ec_gpe_handler)))
+ pr_err("failed to remove gpe handler\n");
+ clear_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
+ }

if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
@@ -1340,12 +1345,7 @@ static void ec_remove_handlers(struct acpi_ec *ec)
clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
}

- if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {
- if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
- &acpi_ec_gpe_handler)))
- pr_err("failed to remove gpe handler\n");
- clear_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
- }
+ acpi_ec_stop(ec, false);
}

static struct acpi_ec *acpi_ec_alloc(void)
--
1.7.10