Commit 32ece31d authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

ACPI: PM: s2idle: Only retrieve constraints when needed 



The evaluation of LPS0 _DSM Function 1 in lps0_device_attach() may be
useless if pm_debug_messages_on is never set.

For this reason, instead of evaluating it in lps0_device_attach(), do
that in a new .begin() callback for s2idle, acpi_s2idle_begin_lps0(),
only when pm_debug_messages_on is set at that point.

However, never attempt to evaluate LPS0 _DSM Function 1 more than once
to avoid recurring failures.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: default avatarMario Limonciello (AMD) <superm1@kernel.org>
Link: https://patch.msgid.link/3027060.e9J7NaK4W3@rafael.j.wysocki
parent bfc09902

drivers/acpi/x86/s2idle.c

+23 −6
Original line number Diff line number Diff line
@@ -303,6 +303,9 @@ static void lpi_check_constraints(void) 
{

	struct lpi_constraints *entry;



	if (IS_ERR_OR_NULL(lpi_constraints_table))

		return;



	for_each_lpi_constraint(entry) {

		struct acpi_device *adev = acpi_fetch_acpi_dev(entry->handle);
@@ -484,11 +487,6 @@ static int lps0_device_attach(struct acpi_device *adev, 


	lps0_device_handle = adev->handle;



	if (acpi_s2idle_vendor_amd())

		lpi_device_get_constraints_amd();

	else

		lpi_device_get_constraints();



	/*

	 * Use suspend-to-idle by default if ACPI_FADT_LOW_POWER_S0 is set in

	 * the FADT and the default suspend mode was not set from the command
@@ -515,6 +513,25 @@ static struct acpi_scan_handler lps0_handler = { 
	.attach = lps0_device_attach,

};



static int acpi_s2idle_begin_lps0(void)

{

	if (pm_debug_messages_on && !lpi_constraints_table) {

		if (acpi_s2idle_vendor_amd())

			lpi_device_get_constraints_amd();

		else

			lpi_device_get_constraints();



		/*

		 * Try to retrieve the constraints only once because failures

		 * to do so usually are sticky.

		 */

		if (!lpi_constraints_table)

			lpi_constraints_table = ERR_PTR(-ENODATA);

	}



	return acpi_s2idle_begin();

}



static int acpi_s2idle_prepare_late_lps0(void)

{

	struct acpi_s2idle_dev_ops *handler;
@@ -612,7 +629,7 @@ static void acpi_s2idle_restore_early_lps0(void) 
}



static const struct platform_s2idle_ops acpi_s2idle_ops_lps0 = {

	.begin = acpi_s2idle_begin,

	.begin = acpi_s2idle_begin_lps0,

	.prepare = acpi_s2idle_prepare,

	.prepare_late = acpi_s2idle_prepare_late_lps0,

	.check = acpi_s2idle_check_lps0,