From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([208.118.235.92]:34913)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <benh@kernel.crashing.org>) id 1SXtlK-0007Td-06
	for qemu-devel@nongnu.org; Fri, 25 May 2012 08:37:03 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <benh@kernel.crashing.org>) id 1SXtlF-0000R2-97
	for qemu-devel@nongnu.org; Fri, 25 May 2012 08:36:57 -0400
Received: from gate.crashing.org ([63.228.1.57]:39385)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <benh@kernel.crashing.org>) id 1SXtlE-0000Qn-T7
	for qemu-devel@nongnu.org; Fri, 25 May 2012 08:36:53 -0400
Message-ID: <1337949400.16119.25.camel@pasglop>
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: Fri, 25 May 2012 22:36:40 +1000
In-Reply-To: <1337948650.4714.88.camel@ul30vt>
References: <4FBF3627.3030504@ozlabs.ru> <1337934518.16119.15.camel@pasglop>
	<1337948650.4714.88.camel@ul30vt>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
Mime-Version: 1.0
Subject: Re: [Qemu-devel] [RFC PATCH] vfio: add fixup for broken PCI devices
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Alex Williamson <alex.williamson@redhat.com>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>, qemu-devel@nongnu.org, Alex Graf <agraf@suse.de>, kvm@vger.kernel.org, David Gibson <david@gibson.dropbear.id.au>

On Fri, 2012-05-25 at 06:24 -0600, Alex Williamson wrote:
> > > To eliminate such effect, some quirk should be called. The
> proposed
> > > pci_fixup_final does its job well for mentioned NEC PCI USB but
> not
> > > sure if it is 100% correct.
> > 
> > I think we should create a new quirk category... call it
> pci_fixup_reset
> > or something like that, which is responsible for blasting the thing
> into
> > submission when ownership changes.
> > 
> > We'll need these for more than just USB I suspect.
> 
> We already have pci_dev_specific_reset() called from pci_dev_reset().
> Does this device support any of the standard reset mechanisms?  It
> would
> be nice to know what within the final fixups keeps this device
> working.
> Thanks, 

Well, HW is HW ... it's going to be broken one way or another. Reset is
no exception, and we already have a way to deal with that sort of
breakage via the quirks. They are already divided in several categories
(early, normal, final, ...), I suggest we just add one for reset. No
point re-inventing a callback mechanism when we already have one.

Cheers,
Ben.