[PATCH 2/2] ACPI / EC: Fix a regression related to the PM ops support of ECDT device

From: Lv Zheng
Date: Tue Sep 26 2017 - 04:54:51 EST


On platforms (ASUS X550ZE and possibly all ASUS X series) with valid ECDT
EC but invalid DSDT EC, EC PM ops won't be invoked as ECDT EC is not an
ACPI device. Thus the following commit actually removed post-resume
acpi_ec_enable_event() invocation for such platforms, and triggered a
regression on them that after being resumed, EC (actually should be ECDT)
driver stops handling EC events:
Commit: c2b46d679b30c5c0d7eb47a21085943242bdd8dc
Subject: ACPI / EC: Add PM operations to improve event handling for resume process
Notice that the root cause actually is "ECDT is not an ACPI device" rather
than "the timing of acpi_ec_enable_event() invocation", this patch fixes
this issue by enumerating ECDT EC as an ACPI device. Due to the existence
of the noirq stage, the ability of tuning the timing of
acpi_ec_enable_event() invocation is still meaningful.

This patch is a little bit different from the posted fix by moving
acpi_config_boot_ec() from acpi_ec_ecdt_start() to acpi_ec_add() to make
sure that EC event handling won't be stopped as long as the ACPI EC driver
is bound. Thus the following sequence shouldn't disable EC event handling:
unbind,suspend,resume,bind.

Fixes: c2b46d679b30 (ACPI / EC: Add PM operations to improve event handling for resume process)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=196847
Reported-by: Luya Tshimbalanga <luya@xxxxxxxxxxxxxxxxx>
Tested-by: Luya Tshimbalanga <luya@xxxxxxxxxxxxxxxxx>
Cc: 4.9+ <stable@xxxxxxxxxxxxxxx> # 4.9+
Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
---
drivers/acpi/ec.c | 69 +++++++++++++++++++++++++++++----------------
drivers/acpi/internal.h | 1 +
drivers/acpi/scan.c | 21 ++++++++++++++
include/acpi/acpi_bus.h | 1 +
include/acpi/acpi_drivers.h | 1 +
5 files changed, 69 insertions(+), 24 deletions(-)

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 82b3ce5..df84246 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -1597,32 +1597,41 @@ static int acpi_ec_add(struct acpi_device *device)
{
struct acpi_ec *ec = NULL;
int ret;
+ bool is_ecdt = false;
+ acpi_status status;

strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
strcpy(acpi_device_class(device), ACPI_EC_CLASS);

- ec = acpi_ec_alloc();
- if (!ec)
- return -ENOMEM;
- if (ec_parse_device(device->handle, 0, ec, NULL) !=
- AE_CTRL_TERMINATE) {
+ if (!strcmp(acpi_device_hid(device), ACPI_ECDT_HID)) {
+ is_ecdt = true;
+ ec = boot_ec;
+ } else {
+ ec = acpi_ec_alloc();
+ if (!ec)
+ return -ENOMEM;
+ status = ec_parse_device(device->handle, 0, ec, NULL);
+ if (status != AE_CTRL_TERMINATE) {
ret = -EINVAL;
goto err_alloc;
+ }
}

if (acpi_is_boot_ec(ec)) {
- boot_ec_is_ecdt = false;
- /*
- * Trust PNP0C09 namespace location rather than ECDT ID.
- *
- * But trust ECDT GPE rather than _GPE because of ASUS quirks,
- * so do not change boot_ec->gpe to ec->gpe.
- */
- boot_ec->handle = ec->handle;
- acpi_handle_debug(ec->handle, "duplicated.\n");
- acpi_ec_free(ec);
- ec = boot_ec;
- ret = acpi_config_boot_ec(ec, ec->handle, true, false);
+ boot_ec_is_ecdt = is_ecdt;
+ if (!is_ecdt) {
+ /*
+ * Trust PNP0C09 namespace location rather than
+ * ECDT ID. But trust ECDT GPE rather than _GPE
+ * because of ASUS quirks, so do not change
+ * boot_ec->gpe to ec->gpe.
+ */
+ boot_ec->handle = ec->handle;
+ acpi_handle_debug(ec->handle, "duplicated.\n");
+ acpi_ec_free(ec);
+ ec = boot_ec;
+ }
+ ret = acpi_config_boot_ec(ec, ec->handle, true, is_ecdt);
} else
ret = acpi_ec_setup(ec, true);
if (ret)
@@ -1635,8 +1644,10 @@ static int acpi_ec_add(struct acpi_device *device)
ret = !!request_region(ec->command_addr, 1, "EC cmd");
WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);

- /* Reprobe devices depending on the EC */
- acpi_walk_dep_device_list(ec->handle);
+ if (!is_ecdt) {
+ /* Reprobe devices depending on the EC */
+ acpi_walk_dep_device_list(ec->handle);
+ }
acpi_handle_debug(ec->handle, "enumerated.\n");
return 0;

@@ -1692,6 +1703,7 @@ ec_parse_io_ports(struct acpi_resource *resource, void *context)

static const struct acpi_device_id ec_device_ids[] = {
{"PNP0C09", 0},
+ {ACPI_ECDT_HID, 0},
{"", 0},
};

@@ -1764,11 +1776,14 @@ static int __init acpi_ec_ecdt_start(void)
* Note: ec->handle can be valid if this function is called after
* acpi_ec_add(), hence the fast path.
*/
- if (boot_ec->handle != ACPI_ROOT_OBJECT)
- handle = boot_ec->handle;
- else if (!acpi_ec_ecdt_get_handle(&handle))
- return -ENODEV;
- return acpi_config_boot_ec(boot_ec, handle, true, true);
+ if (boot_ec->handle == ACPI_ROOT_OBJECT) {
+ if (!acpi_ec_ecdt_get_handle(&handle))
+ return -ENODEV;
+ boot_ec->handle = handle;
+ }
+
+ /* Register to ACPI bus with PM ops attached */
+ return acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
}

#if 0
@@ -2020,6 +2035,12 @@ int __init acpi_ec_init(void)

/* Drivers must be started after acpi_ec_query_init() */
dsdt_fail = acpi_bus_register_driver(&acpi_ec_driver);
+ /*
+ * Register ECDT to ACPI bus only when PNP0C09 probe fails. This is
+ * useful for platforms (confirmed on ASUS X550ZE) with valid ECDT
+ * settings but invalid DSDT settings.
+ * https://bugzilla.kernel.org/show_bug.cgi?id=196847
+ */
ecdt_fail = acpi_ec_ecdt_start();
return ecdt_fail && dsdt_fail ? -ENODEV : 0;
}
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 4361c44..ede83d3 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -115,6 +115,7 @@ bool acpi_device_is_present(const struct acpi_device *adev);
bool acpi_device_is_battery(struct acpi_device *adev);
bool acpi_device_is_first_physical_node(struct acpi_device *adev,
const struct device *dev);
+int acpi_bus_register_early_device(int type);

/* --------------------------------------------------------------------------
Device Matching and Notification
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 602f8ff..2f2f503 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1024,6 +1024,9 @@ static void acpi_device_get_busid(struct acpi_device *device)
case ACPI_BUS_TYPE_SLEEP_BUTTON:
strcpy(device->pnp.bus_id, "SLPF");
break;
+ case ACPI_BUS_TYPE_ECDT_EC:
+ strcpy(device->pnp.bus_id, "ECDT");
+ break;
default:
acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
/* Clean up trailing underscores (if any) */
@@ -1304,6 +1307,9 @@ static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
case ACPI_BUS_TYPE_SLEEP_BUTTON:
acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
break;
+ case ACPI_BUS_TYPE_ECDT_EC:
+ acpi_add_id(pnp, ACPI_ECDT_HID);
+ break;
}
}

@@ -2049,6 +2055,21 @@ void acpi_bus_trim(struct acpi_device *adev)
}
EXPORT_SYMBOL_GPL(acpi_bus_trim);

+int acpi_bus_register_early_device(int type)
+{
+ struct acpi_device *device = NULL;
+ int result;
+
+ result = acpi_add_single_object(&device, NULL,
+ type, ACPI_STA_DEFAULT);
+ if (result)
+ return result;
+
+ device->flags.match_driver = true;
+ return device_attach(&device->dev);
+}
+EXPORT_SYMBOL_GPL(acpi_bus_register_early_device);
+
static int acpi_bus_scan_fixed(void)
{
int result = 0;
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index fa15052..324a04d 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -105,6 +105,7 @@ enum acpi_bus_device_type {
ACPI_BUS_TYPE_THERMAL,
ACPI_BUS_TYPE_POWER_BUTTON,
ACPI_BUS_TYPE_SLEEP_BUTTON,
+ ACPI_BUS_TYPE_ECDT_EC,
ACPI_BUS_DEVICE_TYPE_COUNT
};

diff --git a/include/acpi/acpi_drivers.h b/include/acpi/acpi_drivers.h
index 29c6912..fd0aba7 100644
--- a/include/acpi/acpi_drivers.h
+++ b/include/acpi/acpi_drivers.h
@@ -58,6 +58,7 @@
#define ACPI_VIDEO_HID "LNXVIDEO"
#define ACPI_BAY_HID "LNXIOBAY"
#define ACPI_DOCK_HID "LNXDOCK"
+#define ACPI_ECDT_HID "LNXECDT"
/* Quirk for broken IBM BIOSes */
#define ACPI_SMBUS_IBM_HID "SMBUSIBM"

--
2.7.4