Re: [PATCH v2] parport: register driver later

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Apr 05, 2016 at 06:47:36PM +0530, Sudip Mukherjee wrote:
> On Tuesday 05 April 2016 06:28 PM, Greg KH wrote:
> > On Tue, Apr 05, 2016 at 06:26:08AM +0100, Sudip Mukherjee wrote:
> > > On Mon, Mar 07, 2016 at 10:32:55AM -0700, Ross Zwisler wrote:
> > > > On Sun, Mar 06, 2016 at 08:40:10PM +0530, Sudip Mukherjee wrote:
> > > > > If the parport bus is not yet registered and any device using parallel
> > > > > port tries to register with the bus we get a stackdump with a message
> > > > > of Kernel bug.
> > > > > 
> > > > > Reported-by: Fengguang Wu <fengguang.wu@intel.com>
> > > > > Cc: <stable@vger.kernel.org> # 4.2+
> > > > > Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
> > > > > ---
> > > > > 
> > > > > Hi Ross,
> > > > > Can you please test this patch in your setup. This is a respin of the
> > > > > previous patch in another way.
> > > > 
> > > > Yep, this also solves the issue for me.
> > > > 
> > > > Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
> > > 
> > > Hi Greg,
> > > If this patch is ok, can we please have it in v4.6 .
> > > Anyway, the problem patch which this patch tried to fix has already
> > > been reverted by Linus -
> > > 1701f680407c ("Revert "ppdev: use new parport device model"") but we still
> > > can have problem with the other devices that use parport.
> > > 
> > > BTW, I know you are busy, but in these situations where I need to have
> > > the fix urgently in the tree, is there any other way to solve the purpose?
> > > I feel it was incompetency on my part where Linus had to interfere and
> > > revert a patch even though the fix was already posted.
> > 
> > A bit better commit message here would have caused me to notice it.
> > Something like "Revert a broken patch because it crashes all of our
> > machines without it!!!" would be a hint it needed to go in :)
> 
> Well. its actually my fault. Previously I used to ping and remind you if
> there is something urgent which needed to go in before your tree closes. But
> this time I got busy with the job change and traveling and everything was a
> mess on my side.
> So, now that the ppdev patch has been reverted by Linus, what do you suggest
> that we do? I will say, to have this patch as a temporary fix (for other
> devices) while I work on the deferred probe for parport which will solve the
> problem.

Work on deferred probe, you should have time before the 4.7-rc1 merge
window happens.

thanks,

greg k-h