Re: [PATCH 6/6] x86/PCI: quirk Thunderbolt PCI-to-PCI bridges - Greg Kroah-Hartman

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
	Yinghai Lu <yinghai@kernel.org>,
	john.ronciak@intel.com, miles.j.penner@intel.com,
	bruce.w.allan@intel.com,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	Heikki Krogerus <heikki.krogerus@linux.intel.com>,
	linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
	x86@kernel.org
Subject: Re: [PATCH 6/6] x86/PCI: quirk Thunderbolt PCI-to-PCI bridges
Date: Wed, 26 Jun 2013 08:04:07 -0700	[thread overview]
Message-ID: <20130626150407.GB14117@kroah.com> (raw)
In-Reply-To: <20130626121757.GP9294@intel.com>

On Wed, Jun 26, 2013 at 03:17:57PM +0300, Mika Westerberg wrote:
> On Tue, Jun 25, 2013 at 02:15:56PM -0700, Jesse Barnes wrote:
> > On Tue, 25 Jun 2013 19:22:10 +0300
> > Mika Westerberg <mika.westerberg@linux.intel.com> wrote:
> > 
> > > +	if (!(pci_probe & PCI_NOASSIGN_ROMS)) {
> > > +		pr_info("Thunderbolt host router detected disabling ROMs\n");
> > > +		pci_probe |= PCI_NOASSIGN_ROMS;
> > > +	}
> > 
> > I wonder if this should just be the default on x86?  Or do we allocate
> > ROM space to address some other platform where we need it and the BIOS
> > doesn't do it for the devices we care about?
> 
> Good question. In our case it definitely helps to have pci=norom the
> default. Can't tell if it might break something that depends on the current
> behaviour.
> 
> Bjorn, Greg, Rafael,
> 
> What do you think?

I can't recall any specific reason to not do this, so no objection from
me, but make it a nice and small patch that can easily be reverted if
problems show up in the wild :)

thanks,

greg k-h