Hi Lv Zheng,
I encounter a regression with your patch (Linux 3.8-rc5). On my Nvidia Optimus
laptop, I use the bbswitch[1] kernel module to trigger a _PS3 ACPI method call
to turn the video card off.
After this patch, I got the following in my kernel log:
pci 0000:01:00.0: Refused to change power state, currently in D0
ACPI: Cannot transition to non-D0 state from D3
bbswitch: Succesfully loaded. Discrete card 0000:01:00.0 is on
The expected output would be "Discrete card 0000:01:00.0 is off". Printing the
contents of (acpi_device) device->power.state shows FF (ACPI_STATE_UNKNOWN).
Should this condition be excluded from your check or is my hacky module
outdated?
I currently workaround this issue by checking for ACPI_STATE_UNKNOWN. If that
is the value, I assume on (overwrite device->power.state with ACPI_STATE_D0).
Then I call pci_set_power_state(pci_dev, PCI_D3cold).
Regards,
Peter
[1]: https://github.com/Bumblebee-Project/bbswitch
On Thursday 15 November 2012 12:25:01 Lv Zheng wrote:
> No power transitioning from D3 state to a non-D0 state is allowed.
> This patch also cleans up device power updating code in the
> acpi_device_set_power() as it should already been updated in the
> acpi_power_transition().
>
> Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
> ---
> drivers/acpi/bus.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> index 07a20ee..12c1b51 100644
> --- a/drivers/acpi/bus.c
> +++ b/drivers/acpi/bus.c
> @@ -293,6 +293,12 @@ int acpi_device_set_power(struct acpi_device *device,
> int state) " state than parent\n");
> return -ENODEV;
> }
> + if (device->parent->power.state >= ACPI_STATE_D3_HOT &&
> + state != ACPI_STATE_D0) {
> + printk(KERN_WARNING PREFIX
> + "Cannot transition to non-D0 state from D3\n");
> + return -ENODEV;
> + }
>
> /* For D3cold we should execute _PS3, not _PS4. */
> if (state == ACPI_STATE_D3_COLD)
> @@ -341,7 +347,6 @@ int acpi_device_set_power(struct acpi_device *device,
> int state) "Device [%s] failed to transition to %s\n",
> device->pnp.bus_id, state_string(state));
> else {
> - device->power.state = state;
> ACPI_DEBUG_PRINT((ACPI_DB_INFO,
> "Device [%s] transitioned to %s\n",
> device->pnp.bus_id, state_string(state)));
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