Linux hibernation support for loadable drivers

Linux hibernation support for loadable drivers

[AYAN KUMAR HALDER]

Hi,

I am working with the linux hibernation code( swsusp hibernation
framework) on an ARM based custom SOC. I am using some drivers like
Nand Flash Controller driver as loadable modules.

As per my understanding , during hibernation kernel calls suspend for
all the drivers while creating a snapshot. During resume, after the
kernel resumes the snapshot (from late_initcall - software_resme) ,
the kernel calls resume for all the drivers.

As nand and some other drivers do not support suspend/resume, thus
they fail to work on system resume. So is it fine to call
driver_unregister/driver_register during hibernation/resume for the
drivers which do not support suspend/resume. I do not want the user to
manually remove/insert the drivers on suspend/resume.

Regards,
Ayan Kumar Halder

Linux hibernation support for loadable drivers

[Greg KH]

On Fri, Apr 11, 2014 at 06:28:40PM +0530, AYAN KUMAR HALDER wrote:
> Hi,
> 
> I am working with the linux hibernation code( swsusp hibernation
> framework) on an ARM based custom SOC. I am using some drivers like
> Nand Flash Controller driver as loadable modules.
> 
> As per my understanding , during hibernation kernel calls suspend for
> all the drivers while creating a snapshot. During resume, after the
> kernel resumes the snapshot (from late_initcall - software_resme) ,
> the kernel calls resume for all the drivers.
> 
> As nand and some other drivers do not support suspend/resume, thus
> they fail to work on system resume. So is it fine to call
> driver_unregister/driver_register during hibernation/resume for the
> drivers which do not support suspend/resume. I do not want the user to
> manually remove/insert the drivers on suspend/resume.

Don't call unregister/register for suspend/resume, that's overkill and
isn't right.  Have you taken a look at all of the in-kernel
documentation about suspend/resume that is in the Documentation/
directory?  If not, please do so, it should answer these questions for
you as to how to fix up your drivers.

Hope this helps,

greg k-h

Linux hibernation support for loadable drivers

[Ayan Halder]

Hi,



I am working with the linux hibernation code( swsusp hibernation framework) on an ARM based custom SOC. I am using some drivers like Nand Flash Controller driver as loadable modules.

As per my understanding , during hibernation kernel calls suspend for all the drivers while creating a snapshot. During resume, after the kernel resumes the snapshot (from late_initcall - software_resme) , the kernel calls resume for all the drivers.

As nand and some other drivers do not support suspend/resume, thus they fail to work on system resume. So is it fine to call driver_unregister/driver_register during hibernation/resume for the drivers which do not support suspend/resume. I do not want the user to manually remove/insert the drivers on suspend/resume.



Regards,

Ayan Kumar Halder
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