On Saturday, May 26, 2012, Oleksij Rempel wrote:

Am 26.05.2012 08:03, schrieb Oleksij Rempel (fishor):

quoted

Hi,

On 25.05.2012 22:00, Rafael J. Wysocki wrote:

quoted

On Friday, May 25, 2012, Alan Stern wrote:

quoted

Oleksij:

Please take a look at this bug report:

    https://bugzilla.kernel.org/show_bug.cgi?id=43278

Apparently your patch breaks wakeup on this machine by preventing the
USB host controllers from being put into D3.

I think the patch is incorrect, actually.

First, if you look at the first hunk:

-       if (acpi_target_sleep_state>  ACPI_STATE_S0)
+       if (acpi_target_sleep_state>  ACPI_STATE_S0) {
+               acpi_status status;
+
                 acpi_evaluate_integer(handle, acpi_method, NULL,&d_min);

+               if (device_may_wakeup(dev)) {
+                       acpi_method[3] = 'W';
+                       status = acpi_evaluate_integer(handle,
acpi_method,
+                                                      NULL,&d_max);
+                       if (ACPI_FAILURE(status))
+                               d_max = d_min;
+               }
+       }

it will do something like this: if the device is wakeup-capable, get
d_max
from _SxW, unless it fails.  However, the code just below in that
function:

    if (acpi_target_sleep_state == ACPI_STATE_S0 ||
        (device_may_wakeup(dev)&&
    adev->wakeup.sleep_state<= acpi_target_sleep_state)) {
        acpi_status status;

        acpi_method[3] = 'W';
        status = acpi_evaluate_integer(handle, acpi_method, NULL,
                        &d_max);
        if (ACPI_FAILURE(status)) {
            if (acpi_target_sleep_state != ACPI_STATE_S0 ||
                status != AE_NOT_FOUND)
                d_max = d_min;
        } else if (d_max<  d_min) {
            /* Warn the user of the broken DSDT */
            printk(KERN_WARNING "ACPI: Wrong value from %s\n",
                acpi_method);
            /* Sanitize it */
            d_min = d_max;
        }
    }

does _exactly_ the same thing (it only has a more sophisticated error
code path).

Not really correct. The code below check _SxW state on wake up. This
code checks _SxW on suspend.

oops i misreaded the code. it really do the same. except this part is
not executed because of this check: "adev->wakeup.sleep_state <=
acpi_target_sleep_state"

Precisely.

Thanks,
Rafael