Re: [Fwd: [PATCH] [PNP][RFC] Suspend support for PNP bus.]

[Pierre Ossman <drzeus-list@drzeus.cx>]

Dmitry Torokhov wrote:
> On 11/4/05, Pierre Ossman <drzeus-list@drzeus.cx> wrote:
>   
>> Dmitry Torokhov wrote:
>>     
>>> Hmm, would'nt presence of such device stop suspend process? It will
>>> cause pnp_bus_resume to fail too. Perhaps returning 0 in this case is
>>> better.
>>>
>>>
>>>       
>> The problem is that this code is also visited from pnp_activate_dev() &
>> co where this return value is needed. For pnp_stop_dev() the same check
>> (pnp_can_disable()) is performed in the suspend routine to avoid that
>> particular problem. For resume my assumption was that a device that
>> doesn't support activation will not have a driver attached to it.
>> Perhaps this is wrong?
>>
>>     
>
> i8042 registers drivers for keyboard and AUX ports to gather
> information whether the ports are present and what IRQ and IO ports
> shoudl be used to access them. And I have seen a few boxes that do not
> alloe [de]activate these devices.
>
>   

But the activation is performed by the PNP layer when the driver is 
matched with a driver. So the driver isn't really responsible for the 
activation. It can prevent activation through 
PNP_DRIVER_RES_DO_NOT_CHANGE though, but that flag is also checked in 
the suspend routines.

Rgds
Pierre