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authorLv Zheng <lv.zheng@intel.com>2016-07-08 04:25:05 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-07-08 22:44:12 +0300
commitfa5b4a509d7bbba5d45c8ea177bddfd0b618876a (patch)
tree530ec2195a8df480e5e2f197cf21d61cf3143951 /drivers/acpi/ec.c
parenta99cde438de0c4c0cecc1d1af1a55a75b10bfdef (diff)
downloadlinux-fa5b4a509d7bbba5d45c8ea177bddfd0b618876a.tar.xz
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: dcf15cbded656a12335bc4151f3f75f10080a375 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: dcf15cbded65 (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: Wolfram Sang <wsa@the-dreams.de> Reported-by: Nicholas <nkudriavtsev@gmail.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/ec.c')
-rw-r--r--drivers/acpi/ec.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 73c76d646064..290d6f5be44b 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -1331,8 +1331,6 @@ 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_EC_HANDLER_INSTALLED, &ec->flags)) {
if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
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);
}
+ /*
+ * 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 (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
&acpi_ec_gpe_handler)))