From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
To: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Lukas Wunner <lukas@wunner.de>,
iommu@lists.linux-foundation.org, Joerg Roedel <joro@8bytes.org>,
David Woodhouse <dwmw2@infradead.org>,
Lu Baolu <baolu.lu@linux.intel.com>,
Ashok Raj <ashok.raj@intel.com>,
Bjorn Helgaas <bhelgaas@google.com>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Jacob jun Pan <jacob.jun.pan@intel.com>,
Andreas Noever <andreas.noever@gmail.com>,
Michael Jamet <michael.jamet@intel.com>,
Yehezkel Bernat <YehezkelShB@gmail.com>,
Christian Kellner <ckellner@redhat.com>,
Mario.Limonciello@dell.com,
Anthony Wong <anthony.wong@canonical.com>,
linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/4] PCI / ACPI: Identify external PCI devices
Date: Thu, 15 Nov 2018 11:13:56 +0000 [thread overview]
Message-ID: <20181115111356.GA599@e107981-ln.cambridge.arm.com> (raw)
In-Reply-To: <20181115102239.GU2500@lahna.fi.intel.com>
On Thu, Nov 15, 2018 at 12:22:39PM +0200, Mika Westerberg wrote:
> On Tue, Nov 13, 2018 at 11:45:36AM +0000, Lorenzo Pieralisi wrote:
> > On Tue, Nov 13, 2018 at 01:27:00PM +0200, Mika Westerberg wrote:
> >
> > [...]
> >
> > > > To be frank the concept (and Microsoft _DSD bindings) seems a bit vague
> > > > and not thoroughly defined and I would question its detection at
> > > > PCI/ACPI core level, I would hope this can be clarified at ACPI
> > > > specification level, at least.
> > >
> > > I guess that is the way they envision to use _DSD. Instead of having
> > > single UUID that covers all properties (like what we have with device
> > > properties) they have one UUID per property "class". I certainly hope we
> > > don't need to keep extending prp_guids[] array each time they invent
> > > another "class" of properties.
> >
> > It is even worse than that. This is a unilateral/obscure change that
> > won't be part of ACPI specifications (I guess it was easier to add a
> > UUID than add this to the ACPI specifications through the AWSG) but it
> > is still supposed to be applicable to ACPI PCI bindings on any
> > platforms/arches; this way of adding bindings does not work and it
> > has to be rectified.
>
> I agree.
>
> For the existing property "classes" such as the one here I don't think
> we can do anything. There are systems already with these included in
> their ACPI tables.
>
> I wonder if you have any objections regarding this patch?
I have strong objections to the way these bindings have been forced upon
everybody; if that's the way *generic* ACPI bindings are specified I
wonder why there still exists an ACPI specification and related working
group.
I personally (but that's Bjorn and Rafael choice) think that this is
not a change that belongs in PCI core, ACPI bindings are ill-defined
and device tree bindings are non-existing.
At the very least Microsoft should be asked to publish and discuss
these bindings within the ACPI and UEFI forums.
Lorenzo
next prev parent reply other threads:[~2018-11-15 11:14 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-12 16:06 [PATCH 0/4] PCI / iommu / thunderbolt: IOMMU based DMA protection Mika Westerberg
2018-11-12 16:06 ` [PATCH 1/4] PCI / ACPI: Identify external PCI devices Mika Westerberg
2018-11-12 18:02 ` Lukas Wunner
2018-11-13 10:56 ` Lorenzo Pieralisi
2018-11-13 11:27 ` Mika Westerberg
2018-11-13 11:45 ` Lorenzo Pieralisi
2018-11-15 10:22 ` Mika Westerberg
2018-11-15 11:13 ` Lorenzo Pieralisi [this message]
2018-11-15 11:37 ` Mika Westerberg
2018-11-15 12:07 ` Lukas Wunner
2018-11-15 12:16 ` Mika Westerberg
2018-11-15 17:46 ` Lorenzo Pieralisi
2018-11-15 17:58 ` Yehezkel Bernat
2018-11-15 19:10 ` Mika Westerberg
2018-11-15 19:27 ` Lukas Wunner
2018-11-15 19:32 ` Mika Westerberg
2018-11-16 9:18 ` Christoph Hellwig
2018-11-16 9:32 ` Mika Westerberg
2018-11-22 10:48 ` Mika Westerberg
2018-11-22 10:59 ` Christoph Hellwig
2018-11-15 19:00 ` Mika Westerberg
2018-11-15 19:33 ` Mario.Limonciello
2018-11-16 10:57 ` Lorenzo Pieralisi
2018-11-20 21:43 ` Rafael J. Wysocki
2018-11-21 12:40 ` Lorenzo Pieralisi
2018-11-16 7:01 ` Mika Westerberg
2018-11-12 16:06 ` [PATCH 2/4] iommu/vt-d: Force IOMMU on for platform opt in hint Mika Westerberg
2018-11-12 17:49 ` Raj, Ashok
2018-11-12 18:09 ` Alex Williamson
2018-11-12 19:51 ` Raj, Ashok
2018-11-12 16:06 ` [PATCH 3/4] iommu/vt-d: Do not enable ATS for external devices Mika Westerberg
2018-11-12 17:53 ` Raj, Ashok
2018-11-12 16:06 ` [PATCH 4/4] thunderbolt: Export IOMMU based DMA protection support to userspace Mika Westerberg
2018-11-12 16:22 ` Mario.Limonciello
2018-11-13 10:36 ` Mika Westerberg
2018-11-12 16:59 ` Yehezkel Bernat
2018-11-13 10:55 ` Mika Westerberg
2018-11-13 11:13 ` Yehezkel Bernat
2018-11-13 11:40 ` Mika Westerberg
2018-11-13 14:42 ` Yehezkel Bernat
[not found] ` <20181113152038.GD2500@lahna.fi.intel.com>
2018-11-13 15:38 ` Yehezkel Bernat
2018-11-13 16:12 ` Mika Westerberg
2018-11-12 18:12 ` [PATCH 0/4] PCI / iommu / thunderbolt: IOMMU based DMA protection Lukas Wunner
2018-11-12 19:04 ` Yehezkel Bernat
2018-11-13 11:13 ` Mika Westerberg
2018-11-13 8:54 ` Joerg Roedel
2018-11-13 11:32 ` Mika Westerberg
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