RE: 2.6.12-rc1-mm1: Kernel BUG at pci:389

From: Li, Shaohua
Date: Tue Mar 22 2005 - 07:16:03 EST


>
>> > Yes, but it is needed. There are many drivers, and they look at
>> > numerical value of PMSG_*. I'm proceeding in steps. I hopefully
killed
>> > all direct accesses to the constants, and will switch constants to
>> > something else... But that is going to be tommorow (need some
sleep).
>> The patches are going to acquire correct PCI device sleep state for
>> suspend/resume. We discussed the issue several months ago. My plan is
we
>> first introduce 'platform_pci_set_power_state', then merge the
>> 'platform_pci_choose_state' patch after Pavel's pm_message_t
conversion
>> finished. Maybe Len mislead my comments.
>>
>> Anyway for the callback, my intend is platform_pci_choose_state
accept
>> the pm_message_t parameter, and it return an 'int', since platform
>> method possibly failed and then pci_choose_state translate the return
>> value to pci_power_t.
>
>You can't just retype around like that. You may want it take
>pci_power_t * as an argument, and then return 0/-ENODEV or something
>like that. But you can't retype between int and pm_message_t...
No, taking pci_power_t as an argument is meaningless. For ACPI, we
should know the exact sleep state, pm_message_t will tell us. But I'm ok
to let it return a pci_power_t, and the failure case returns -ENODEV.

>
>Plus that function should have a documentation somewhere!
I will add it.

>
>> > Could you just revert those two patches? First one is very
>> > wrong. Second one might be fixed, but... See comments below.
>> I think the platform_pci_set_power_state should be ok, did you see it
>> causes oops?
>
>No its just ugly and uses __force in "creative" way. That one can be
>recovered.
Do you mean this?

> + static int state_conv[] = {
> + [0] = 0,
> + [1] = 1,
> + [2] = 2,
> + [3] = 3,
> + [4] = 3
> + };
> + int acpi_state = state_conv[(int __force) state];

The table should be
[PCI_D0] = 0,

I'm not sure, but then could we use state_conv[state] directly? It seems
wrong to me (the array accepts a pci_power_t as index?)

Thanks,
Shaohua
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