ACPI fan driver: uninitialized variable when CONFIG_PM is not set

From: Michel Lespinasse
Date: Mon Apr 29 2013 - 08:32:32 EST

In the following code:

static int fan_get_cur_state(struct thermal_cooling_device *cdev, unsigned long
struct acpi_device *device = cdev->devdata;
int result;
int acpi_state;

if (!device)
return -EINVAL;

result = acpi_bus_update_power(device->handle, &acpi_state);
if (result)
return result;

*state = (acpi_state == ACPI_STATE_D3 ? 0 :
(acpi_state == ACPI_STATE_D0 ? 1 : -1));
return 0;

With CONFIG_PM not set, acpi_bus_update_power() returns 0 and does not
initialize acpi_state. This results in acpi_state being used before

(I found out by random chance, as I suppose people don't normally
build without CONFIG_PM anymore ?)

I'm not sure what a proper fix would be, so I'll just report this here
and enable CONFIG_PM locally :)

Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.
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