Commit 98ada3c5 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

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: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 03e9a0e0

drivers/acpi/ec.c

+36 −55
Original line number Diff line number Diff line
@@ -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;



	/* 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;



	/*

	 * 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;

	}



	/* Register to ACPI bus with PM ops attached */

	return acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);

	/* 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 */

drivers/acpi/internal.h

+1 −1
Original line number Diff line number Diff line
@@ -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);

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