Reboot on shutdown with USB 2.0

Reboot on shutdown with USB 2.0

[Michael Madore]

Hi,

I'm having a strange problem regarding ACPI and USB 2.0 devices 
(External CD-Rom, Jaz drive, etc).  Using 2.4.21-pre5 with the latest 
patch if I issue:

shutdown -h now

The machine shuts off, but half a second later the power comes back on. 
 If I unload the echi driver module, the machine shuts off normally.

Any thoughts on what would cause that kind of behavior?

Thanks!

Mike Madore




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RE: Reboot on shutdown with USB 2.0

[Grover, Andrew]

> From: Michael Madore [mailto:mmadore-JChM1cqIHx8AvxtiuMwx3w@public.gmane.org] 

> I'm having a strange problem regarding ACPI and USB 2.0 devices 
> (External CD-Rom, Jaz drive, etc).  Using 2.4.21-pre5 with the latest 
> patch if I issue:
> 
> shutdown -h now
> 
> The machine shuts off, but half a second later the power 
> comes back on. 
>  If I unload the echi driver module, the machine shuts off normally.
> 
> Any thoughts on what would cause that kind of behavior?

Is this an SMP system? Just curious.

What we should be doing (but aren't) is telling each device's driver on
the system to deactivate its device before we turn off the system power.
This gives the driver the chance to disable that device's interrupt
generation. We haven't gotten that far in the driver model work, so what
we are doing is disabling interrupts and then powering down. This mostly
works, but isn't really how we want things to work, and is pretty much
doomed to fail on SMP systems.

I don't know why the ehci device would specifically be the one to cause
problems...

Regards -- Andy


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Re: Reboot on shutdown with USB 2.0

[Michael Madore]

Grover, Andrew wrote:

>>From: Michael Madore [mailto:mmadore-JChM1cqIHx8AvxtiuMwx3w@public.gmane.org] 
>>    
>>
>
>  
>
>>I'm having a strange problem regarding ACPI and USB 2.0 devices 
>>(External CD-Rom, Jaz drive, etc).  Using 2.4.21-pre5 with the latest 
>>patch if I issue:
>>
>>shutdown -h now
>>
>>The machine shuts off, but half a second later the power 
>>comes back on. 
>> If I unload the echi driver module, the machine shuts off normally.
>>
>>Any thoughts on what would cause that kind of behavior?
>>    
>>
>
>Is this an SMP system? Just curious.
>  
>
Yes, this particular system is SMP.  I'll have to try it with a UP 
kernel just to see if the problem persists.

>What we should be doing (but aren't) is telling each device's driver on
>the system to deactivate its device before we turn off the system power.
>This gives the driver the chance to disable that device's interrupt
>generation. We haven't gotten that far in the driver model work, so what
>we are doing is disabling interrupts and then powering down. This mostly
>works, but isn't really how we want things to work, and is pretty much
>doomed to fail on SMP systems.
>
>I don't know why the ehci device would specifically be the one to cause
>problems...
>  
>
That makes sense, thanks for the explaination.  As a workaround, perhaps 
we can modify the init scripts to unload the ehci driver during shutdown.

Mike Madore



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