From: Bjorn Helgaas <helgaas@kernel.org>
To: "Yong, Jonathan" <jonathan.yong@intel.com>
Cc: linux-pci@vger.kernel.org, bhelgaas@google.com
Subject: Re: [PATCH v5] PCI: PTM preliminary implementation
Date: Sat, 18 Jun 2016 13:15:46 -0500 [thread overview]
Message-ID: <20160618181546.GC20504@localhost> (raw)
In-Reply-To: <575F5EAC.2030904@intel.com>
On Tue, Jun 14, 2016 at 09:32:28AM +0800, Yong, Jonathan wrote:
> On 06/14/2016 02:56, Bjorn Helgaas wrote:
> >I'm also a little confused about how Root Complex Integrated Endpoints
> >are supposed to use PTM, since they don't have an upstream bridge.
> >Maybe it has to do with an RCRB (Root Complex Register Block, spec
> >r3.1, sec 7.2.3)? I don't think Linux really has any support for that
> >(yet).
>
> The spec (7.32.3 PTM Control Register) says:
>
> For Root Complex Integrated Endpoints, system software must set this
> field to the value reported in the Local Clock Granularity field by
> the associated PTM Time Source.
>
> I'm not familiar with RC integrated endpoints either. I'm guessing
> whatever device 0, function 0 on the "bus"? Just copy the
> granularity value over?
I don't know what the answer is, but I don't think device 0, function
0 is it. There's no reason to expect that to be related to an
integrated endpoint.
I suspect it has to do with the RCRB, but I haven't had a chance to
work through that yet. For now, I just made it use zero (unknown)
for the effective granularity of integrated endpoints.
Bjorn
next prev parent reply other threads:[~2016-06-18 18:15 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-11 8:47 [PATCH v5] PCI: PTM Driver Yong, Jonathan
2016-05-11 8:47 ` [PATCH v5] PCI: PTM preliminary implementation Yong, Jonathan
2016-06-12 22:18 ` Bjorn Helgaas
2016-06-13 2:59 ` Yong, Jonathan
2016-06-13 13:45 ` Bjorn Helgaas
2016-06-13 18:56 ` Bjorn Helgaas
2016-06-14 1:32 ` Yong, Jonathan
2016-06-18 18:15 ` Bjorn Helgaas [this message]
2016-05-24 3:59 ` [PATCH v5] PCI: PTM Driver Yong, Jonathan
2016-05-31 0:17 ` Yong, Jonathan
2016-06-09 6:32 ` Yong, Jonathan
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