From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
Len Brown <lenb@kernel.org>,
Valerio Passini <passini.valerio@gmail.com>,
linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org,
Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: Re: [PATCH] ACPI / hotplug / PCI: Allocate resources directly under the non-hotplug bridge
Date: Thu, 7 Nov 2019 16:02:59 +0200 [thread overview]
Message-ID: <20191107140259.GN2552@lahna.fi.intel.com> (raw)
In-Reply-To: <20191107135246.GA90684@google.com>
On Thu, Nov 07, 2019 at 07:52:46AM -0600, Bjorn Helgaas wrote:
> > > What would happen if a device below one of the non-hotplug bridges,
> > > e.g., 3a:00.0, had an I/O BAR? Would this patch still work?
> >
> > I think it would still work because now we call pci_bus_size_bridges()
> > only for non-hotplug bridge which do not have I/O window open so
> > pbus_size_io() fails to find the "free" I/O resource on that bus and the
> > kernel then fails to assign that I/O resource for the device.
>
> Not sure I understand; are you saying that we wouldn't have the EC/GPE
> issue, but we'd be unable to use a device below 3a:00.0 that happened
> to have an I/O BAR?
Yes.
> That doesn't sound optimal because there is I/O space available that
> could be routed to 3a:00.0
If the none of the upstream bridges up to the PCIe root port does not
have I/O window open, I don't think we can do much about it. Unless I'm
missing something of course.
next prev parent reply other threads:[~2019-11-07 14:03 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-30 15:05 [PATCH] ACPI / hotplug / PCI: Allocate resources directly under the non-hotplug bridge Mika Westerberg
2019-11-06 12:28 ` Rafael J. Wysocki
2019-11-06 23:24 ` Bjorn Helgaas
2019-11-07 1:05 ` Benjamin Herrenschmidt
2019-11-07 9:03 ` Mika Westerberg
2019-11-07 13:52 ` Bjorn Helgaas
2019-11-07 14:02 ` Mika Westerberg [this message]
2019-11-07 14:40 ` Bjorn Helgaas
2019-11-07 14:52 ` Mika Westerberg
2019-11-12 0:19 ` Bjorn Helgaas
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