Re: [linuxppc-dev] Unbinding device from a driver

Re: [linuxppc-dev] Unbinding device from a driver

[Scott Wood]

On 07/04/2013 05:35:28 AM, Gupta Ruchika-R66431 wrote:
> Hi,
> 
> 
> 
> I am trying to unbind a platform device from a driver. Even when the  
> remove function of the device returns an EBUSY error, the device is  
> unbound from the driver. Is this the right behavior ? Why does kernel  
> forcefully unbind the device even if device remove function returns  
> an error ?

 From looking at the code, it seems it's not allowed for a driver to  
refuse the unbinding.  If you can't unbind yet, you need to block until  
you can (and take measures to ensure that it won't take too long).

I don't know the history of why the remove method can return an error  
even though nothing seems to check it.

> root@p4080ds: ls
> 
> bind  ffe301000.jr  ffe302000.jr  ffe303000.jr  ffe304000.jr  uevent   
> unbind
> 
> 
> 
> root@p4080ds: echo ffe301000.jr > unbind
> 
> In caam_jr_remove
> 
> caam_jr ffe301000.jr: Device Busy

Is the caam_jr driver printing this, or the device model infrastructure?

-Scott

RE: [linuxppc-dev] Unbinding device from a driver

[Gupta Ruchika-R66431]

> -----Original Message-----
> From: Wood Scott-B07421
> Sent: Tuesday, July 09, 2013 5:04 AM
> To: Gupta Ruchika-R66431
> Cc: linuxppc-dev@linux.freescale.net; linux-kernel@vger.kernel.org
> Subject: Re: [linuxppc-dev] Unbinding device from a driver
> 
> On 07/04/2013 05:35:28 AM, Gupta Ruchika-R66431 wrote:
> > Hi,
> >
> >
> >
> > I am trying to unbind a platform device from a driver. Even when the
> > remove function of the device returns an EBUSY error, the device is
> > unbound from the driver. Is this the right behavior ? Why does kernel
> > forcefully unbind the device even if device remove function returns an
> > error ?
> 
>  From looking at the code, it seems it's not allowed for a driver to refuse
> the unbinding.  If you can't unbind yet, you need to block until you can
> (and take measures to ensure that it won't take too long).
> 
> I don't know the history of why the remove method can return an error even
> though nothing seems to check it.
> 
> > root@p4080ds: ls
> >
> > bind  ffe301000.jr  ffe302000.jr  ffe303000.jr  ffe304000.jr  uevent
> > unbind
> >
> >
> >
> > root@p4080ds: echo ffe301000.jr > unbind
> >
> > In caam_jr_remove
> >
> > caam_jr ffe301000.jr: Device Busy
> 
> Is the caam_jr driver printing this, or the device model infrastructure?
This is being printed by jr driver.

Ruchika
> 
> -Scott