From 98ada3c59d05e6c41f35fe1f7e5a550c1536be45 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 6 Mar 2020 00:14:35 +0100 Subject: ACPI: EC: Simplify acpi_ec_ecdt_start() and acpi_ec_init() Notice that the return value of acpi_ec_init() is discarded anyway, so it can be void and it doesn't need to check the return values of acpi_bus_register_driver() and acpi_ec_ecdt_start() called by it. Thus the latter can be void too and it really has nothing to do if acpi_ec_add() has already found an EC matching the boot one in the namespace. Also, acpi_ec_ecdt_get_handle() can be folded into it. Modify the code accordingly and while at it create a propoer kerneldoc comment to document acpi_ec_ecdt_start() and move the remark regarding ASUS X550ZE along with the related bug URL from acpi_ec_init() into that comment. Additionally, fix up a stale comment in acpi_ec_init(). Signed-off-by: Rafael J. Wysocki --- drivers/acpi/ec.c | 91 +++++++++++++++++++------------------------------ drivers/acpi/internal.h | 2 +- 2 files changed, 37 insertions(+), 56 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index 47baeec9190d..9e7ee6ae4706 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -1594,25 +1594,6 @@ static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device) return ret; } -static bool acpi_ec_ecdt_get_handle(acpi_handle *phandle) -{ - struct acpi_table_ecdt *ecdt_ptr; - acpi_status status; - acpi_handle handle; - - status = acpi_get_table(ACPI_SIG_ECDT, 1, - (struct acpi_table_header **)&ecdt_ptr); - if (ACPI_FAILURE(status)) - return false; - - status = acpi_get_handle(NULL, ecdt_ptr->id, &handle); - if (ACPI_FAILURE(status)) - return false; - - *phandle = handle; - return true; -} - static int acpi_ec_add(struct acpi_device *device) { struct acpi_ec *ec; @@ -1784,35 +1765,42 @@ void __init acpi_ec_dsdt_probe(void) } /* - * If the DSDT EC is not functioning, we still need to prepare a fully - * functioning ECDT EC first in order to handle the events. - * https://bugzilla.kernel.org/show_bug.cgi?id=115021 + * acpi_ec_ecdt_start - Finalize the boot ECDT EC initialization. + * + * First, look for an ACPI handle for the boot ECDT EC if acpi_ec_add() has not + * found a matching object in the namespace. + * + * Next, in case the DSDT EC is not functioning, it is still necessary to + * provide a functional ECDT EC to handle events, so add an extra device object + * to represent it (see https://bugzilla.kernel.org/show_bug.cgi?id=115021). + * + * This is useful on platforms with valid ECDT and invalid DSDT EC settings, + * like ASUS X550ZE (see https://bugzilla.kernel.org/show_bug.cgi?id=196847). */ -static int __init acpi_ec_ecdt_start(void) +static void __init acpi_ec_ecdt_start(void) { + struct acpi_table_ecdt *ecdt_ptr; acpi_handle handle; + acpi_status status; - if (!boot_ec) - return -ENODEV; - /* In case acpi_ec_ecdt_start() is called after acpi_ec_add() */ - if (!boot_ec_is_ecdt) - return -ENODEV; + /* Bail out if a matching EC has been found in the namespace. */ + if (!boot_ec || boot_ec->handle != ACPI_ROOT_OBJECT) + return; - /* - * At this point, the namespace and the GPE is initialized, so - * start to find the namespace objects and handle the events. - * - * 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) { - if (!acpi_ec_ecdt_get_handle(&handle)) - return -ENODEV; - boot_ec->handle = handle; - } + /* Look up the object pointed to from the ECDT in the namespace. */ + status = acpi_get_table(ACPI_SIG_ECDT, 1, + (struct acpi_table_header **)&ecdt_ptr); + if (ACPI_FAILURE(status)) + return; + + status = acpi_get_handle(NULL, ecdt_ptr->id, &handle); + if (ACPI_FAILURE(status)) + return; - /* Register to ACPI bus with PM ops attached */ - return acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC); + boot_ec->handle = handle; + + /* Add a special ACPI device object to represent the boot EC. */ + acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC); } #if 0 @@ -2156,14 +2144,13 @@ static const struct dmi_system_id acpi_ec_no_wakeup[] = { { }, }; -int __init acpi_ec_init(void) +void __init acpi_ec_init(void) { int result; - int ecdt_fail, dsdt_fail; result = acpi_ec_init_workqueues(); if (result) - return result; + return; /* * Disable EC wakeup on following systems to prevent periodic @@ -2174,16 +2161,10 @@ int __init acpi_ec_init(void) pr_debug("Disabling EC wakeup on suspend-to-idle\n"); } - /* 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; + /* Driver must be registered after acpi_ec_init_workqueues(). */ + acpi_bus_register_driver(&acpi_ec_driver); + + acpi_ec_ecdt_start(); } /* EC driver currently not unloadable */ diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index 3616daec650b..43411a7457cd 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -190,7 +190,7 @@ extern struct acpi_ec *first_ec; /* External interfaces use first EC only, so remember */ typedef int (*acpi_ec_query_func) (void *data); -int acpi_ec_init(void); +void acpi_ec_init(void); void acpi_ec_ecdt_probe(void); void acpi_ec_dsdt_probe(void); void acpi_ec_block_transactions(void); -- cgit v1.2.3