Subject: [RFC 1/1] Driver Core: don't oops with unregistered driver in driver_find_device()

From: [email-masked] (Greg Kroah-Hartman)
Date: Thu, 10 May 2012 07:11:30 -0700

On Thu, May 10, 2012 at 10:35:02AM +0300, Hiroshi DOYU wrote:
> driver_find_device() can be called with an unregistered driver.

Who does that?  Where in the kernel?  Why would you try to do that?

> Need to check driver_private to see if it's populated or not,
> especially under deferrable probe.

Hm, I don't know if this will really catch a driver that was registered
and then was unregistered, right?  It seems like moving the real problem
somewhere else, why not fix the original issue instead?

> Signed-off-by: Hiroshi DOYU <[email-masked]>
> ---
> In [PATCHv5 2/3] ARM: tegra: Add SMMU enabler in AHB:
>   http://article.gmane.org/gmane.linux.ports.tegra/4658
> 
> "tegra_ahb_driver" may not be populated when it's called.

It can?  I don't see that in that patch.

confused,

greg k-h