[PATCH] ACPI: evaluate _PS3 when entering D3 Cold

Aaron Lu
2012-03-31T10:19:22Z

When entering D3 Cold from a higher device state, evaluate _PS3 first
and then make the proper power transition.
This is used to solve the ZPODD problem on AMD's platform, _PS3 on such
platforms will power off the ODD device and thus make the device enter
D3 cold state.

Signed-off-by: Aaron Lu <aaron.lu@amd.com>
Cc: Andiry Xu <andiry.xu@amd.com>
Cc: Alex He <alex.he@amd.com>
---
drivers/acpi/bus.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 3263b68..68e593f 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -227,6 +227,8 @@ static int __acpi_bus_set_power(struct acpi_device *device, int state)
int result = 0;
acpi_status status = AE_OK;
char object_name[5] = { '_', 'P', 'S', '0' + state, '\0' };
+ struct acpi_device_power_state *ps;
+ u8 explicit_set;

if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
return -EINVAL;
@@ -239,7 +241,8 @@ static int __acpi_bus_set_power(struct acpi_device *device, int state)
return 0;
}

- if (!device->power.states[state].flags.valid) {
+ ps = &device->power.states[state];
+ if (!ps->flags.valid) {
printk(KERN_WARNING PREFIX "Device does not support D%d\n", state);
return -ENODEV;
}
@@ -263,7 +266,7 @@ static int __acpi_bus_set_power(struct acpi_device *device, int state)
if (result)
goto end;
}
- if (device->power.states[state].flags.explicit_set) {
+ if (ps->flags.explicit_set) {
status = acpi_evaluate_object(device->handle,
object_name, NULL, NULL);
if (ACPI_FAILURE(status)) {
@@ -272,7 +275,15 @@ static int __acpi_bus_set_power(struct acpi_device *device, int state)
}
}
} else {
- if (device->power.states[state].flags.explicit_set) {
+ /* If state is D3 Cold, try to evaluate _PS3 first */
+ if (state == ACPI_STATE_D3_COLD) {
+ explicit_set = (ps - 1)->flags.explicit_set;
+ object_name[3] -= 1;
+ }
+ else {
+ explicit_set = ps->flags.explicit_set;
+ }
+ if (explicit_set) {
status = acpi_evaluate_object(device->handle,
object_name, NULL, NULL);
if (ACPI_FAILURE(status)) {
--
1.7.9.2.315.g25a78.dirty