diff options
| author | Tim Van Patten <timvp@google.com> | 2022-04-13 11:53:20 -0600 |
|---|---|---|
| committer | Felix Held <felix-coreboot@felixheld.de> | 2022-04-14 22:30:05 +0000 |
| commit | 3d4665cc71229d0d404035217b6796adc94c9567 (patch) | |
| tree | 59f07e2ea55ea8c2bed06a81bff0354096d8bb10 /src/acpi | |
| parent | e9667f4df146ec82511975175fb03287afde4296 (diff) | |
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>
Diffstat (limited to 'src/acpi')
| -rw-r--r-- | src/acpi/device.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/src/acpi/device.c b/src/acpi/device.c index 1df179bad6..2b085b61a6 100644 --- a/src/acpi/device.c +++ b/src/acpi/device.c @@ -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) { |