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src/acpi/device: Early return in _ON if device already enabled 

If the device has enabled `use_gpio_for_status`, then call the `_STA`
method in `_ON` to determine if the device is already enabled. If it is
already enabled, return early to skip re-enabling the device and
performing the associated sleep.

This change is necessary since the Linux kernel does not call `_STA`
before calling `_ON`.

BRANCH=None
BUG=b:225022810
TEST=Dump SSDT table for guybrush

Signed-off-by: Tim Van Patten <timvp@google.com>
Change-Id: I13aa41766555953b86eded4c72e3b317fe6db5c8
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63613
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
This commit is contained in:
Tim Van Patten 2022-04-13 11:53:20 -06:00 committed by Felix Held
parent e9667f4df1
commit 3d4665cc71
1 changed files with 13 additions and 0 deletions
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13
src/acpi/device.c
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@ -670,6 +670,19 @@ void acpi_device_add_power_res(const struct acpi_power_res_params *params)
/* Method (_ON, 0, Serialized) */
acpigen_write_method_serialized("_ON", 0);
/* Call _STA and early return if the device is already enabled, since the Linux
kernel doesn't check the device status before calling _ON. This avoids
unnecessary delays while booting. */
if (params->use_gpio_for_status) {
/* Local0 = _STA () */
acpigen_write_store();
acpigen_emit_namestring("_STA");
acpigen_emit_byte(LOCAL0_OP);
/* If (( Local0 == ACPI_POWER_RESOURCE_STATUS_ON_OP)) */
acpigen_write_if_lequal_op_op(LOCAL0_OP, ACPI_POWER_RESOURCE_STATUS_ON_OP);
acpigen_write_return_op(ZERO_OP);
acpigen_write_if_end();
}
if (reset_gpio)
acpigen_enable_tx_gpio(params->reset_gpio);
if (enable_gpio) {