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Date: Thu, 28 May 2015 12:23:25 +0530
From: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
To: Felipe Balbi <balbi@ti.com>
Cc: Greg KH <gregkh@linuxfoundation.org>,
        Alan Stern <stern@rowland.harvard.edu>,
        Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        Tal Shorer <tal.shorer@gmail.com>,
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        David Cohen <david.a.cohen@linux.intel.com>,
        Lu Baolu <baolu.lu@linux.intel.com>
Subject: Re: [PATCH] usb: ulpi: don't register drivers if bus doesn't exist
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On Thu, May 28, 2015 at 12:12:56PM +0530, Sudip Mukherjee wrote:
> On Thu, May 28, 2015 at 12:54:59AM -0500, Felipe Balbi wrote:
> > On Thu, May 28, 2015 at 11:09:38AM +0530, Sudip Mukherjee wrote:
> > > On Wed, May 27, 2015 at 08:21:16AM -0700, Greg KH wrote:
> > > > On Wed, May 27, 2015 at 11:16:34AM -0400, Alan Stern wrote:
> > > > > On Wed, 27 May 2015, Heikki Krogerus wrote:
> > > > 
> > > > Maybe we need to test for this in the driver core, not allowing drivers
> > > > for busses that are not registered, that might solve the main problem
> > > > here.  I'll try to look at it tonight.
> > > may i suggest something like this ?
> > > buildtest with allmodconfig and allyesconfig on x86_64.
> > > built and booted on x86.
> > > 
> > > 
> > > diff --git a/drivers/base/bus.c b/drivers/base/bus.c
> > > index 5005924..95cefa0 100644
> > > --- a/drivers/base/bus.c
> > > +++ b/drivers/base/bus.c
> > > @@ -943,6 +943,7 @@ int bus_register(struct bus_type *bus)
> > >  	if (retval)
> > >  		goto bus_groups_fail;
> > >  
> > > +	bus->registered = true;
> > 
> > once set, it's never cleared.
> It should be cleared when we go for bus_unregister.
apart from bus_register we need the check in some other places also.
like bus_create_file().

regards
sudip