Commit fa5b4a50 authored by Lv Zheng's avatar Lv Zheng Committed by Rafael J. Wysocki
Browse files

ACPI / EC: Fix code ordering issue in ec_remove_handlers() 

There is an order issue in ec_remove_handlers() that acpi_ec_stop()
is called before removing the operation region handler. That is
incorrect, because the operation region handler removal triggers
_REG(DISCONNECT) which may result in new EC transactions to carry
out.

That existing issue has been triggered by the following commit:

    Commit: dcf15cbd
    Subject: ACPI / EC: Fix a boot EC regresion by restoring boot EC

which changed the driver to call ec_remove_handlers() after invoking
_REG(CONNECT), so the issue has become visible.

Fixes: dcf15cbd (ACPI / EC: Fix a boot EC regresion by restoring boot EC)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=102421


Reported-and-tested-by: default avatarWolfram Sang <wsa@the-dreams.de>
Reported-by: default avatarNicholas <nkudriavtsev@gmail.com>
Signed-off-by: default avatarLv Zheng <lv.zheng@intel.com>
[ rjw: Changelog ]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent a99cde43

drivers/acpi/ec.c

+13 −2
Original line number Original line Diff line number Diff line
@@ -1331,8 +1331,6 @@ static int ec_install_handlers(struct acpi_ec *ec) 




static void ec_remove_handlers(struct acpi_ec *ec)

static void ec_remove_handlers(struct acpi_ec *ec)

{

{

	acpi_ec_stop(ec, false);



	if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {

	if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {

		if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,

		if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,

					ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))

					ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
@@ -1340,6 +1338,19 @@ static void ec_remove_handlers(struct acpi_ec *ec) 
		clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);

		clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);

	}

	}





	/*

	 * Stops handling the EC transactions after removing the operation

	 * region handler. This is required because _REG(DISCONNECT)

	 * invoked during the removal can result in new EC transactions.

	 *

	 * Flushes the EC requests and thus disables the GPE before

	 * removing the GPE handler. This is required by the current ACPICA

	 * GPE core. ACPICA GPE core will automatically disable a GPE when

	 * it is indicated but there is no way to handle it. So the drivers

	 * must disable the GPEs prior to removing the GPE handlers.

	 */

	acpi_ec_stop(ec, false);



	if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {

	if (test_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags)) {

		if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,

		if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,

					&acpi_ec_gpe_handler)))

					&acpi_ec_gpe_handler)))

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