On 5 Sep, Andrew Morton wrote:
>> On Wed, 05 Sep 2007 19:47:42 +0200 Stefan Richter <[EMAIL PROTECTED]> wrote:
>> >>> Trying to free already-free IRQ 40
>> >>> pci_set_power_state(): 0002:20:0e.0: state=3, current state=5
>> >>> firewire_ohci: pci_set_power_state failed with
>> >>> -22<3>pci_device_suspend(): pci_suspend+0x0/0x9c [firewire_ohci]()
>> >>> returns -22
...
>> The old ohci1394.c used to ignore pci_set_power_state's return value.
>> In the pre 2.6.19-rc1 commit ea6104c22468239083857fa07425c312b1ecb424, I
>> added a fail-on-error. This was toned down to a printk-on-err by pre
>> 2.6.19-rc4 commit 346f5c7ee7fa4ebee0e4c96415a7e59716bfa1d0.
>
> OK.
>
>> This was because of Benjamin Herrenschmidt's regression report:
>> http://lkml.org/lkml/2006/10/24/13
>
> It's not clear _why_ pci_set_power_state() is failing.
The only -22 error path in pci_set_power_state is this:
/* Validate current state:
* Can enter D0 from any state, but if we can only go deeper
* to sleep if we're already in a low power state
*/
if (state != PCI_D0 && dev->current_state > state) {
printk(KERN_ERR "%s(): %s: state=%d, current state=%d\n",
__FUNCTION__, pci_name(dev), state, dev->current_state);
return -EINVAL;
} [...else...]
(There seems to be one "if" too many in the comment.)
dev->current_state was PCI_UNKNOWN, and this is not properly handled by
pci_set_power_state. Some checks later, there is
switch (dev->current_state) {
case PCI_D0:
case PCI_D1:
case PCI_D2:
pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
pmcsr |= state;
break;
case PCI_UNKNOWN: /* Boot-up */
if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
&& !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
need_restore = 1;
/* Fall-through: force to D0 */
default:
pmcsr = 0;
break;
}
But the PCI_UNKNOWN branch will never be reached because of the if ()
clause quoted above.
Also, this FireWire controller here surely had left the boot-up phase
already long ago when the reporter tried to suspend the machine.
--
Stefan Richter
-=====-=-=== =--= --=-=
http://arcgraph.de/sr/
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