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: Mon, 13 Jun 2016 13:56:48 -0500 [thread overview]
Message-ID: <20160613185648.GA6901@localhost> (raw)
In-Reply-To: <1462956446-27361-2-git-send-email-jonathan.yong@intel.com>
On Wed, May 11, 2016 at 08:47:26AM +0000, Yong, Jonathan wrote:
> Simplified Precision Time Measurement driver, activates PTM feature
> if a PCIe PTM requester (as per PCI Express 3.1 Base Specification
> section 7.32)is found, but not before checking if the rest of the
> PCI hierarchy can support it.
>
> The driver does not take part in facilitating PTM conversations,
> neither does it provide any useful services, it is only responsible
> for setting up the required configuration space bits.
I'm not convinced we should blindly enable PTM on every device that
supports it (especially endpoints), and I think the logic here is more
complicated than necessary.
I'm going to post a v6 as a draft. My draft is probably not
complicated *enough*, but maybe we can figure out some point
in the middle.
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).
Bjorn
next prev parent reply other threads:[~2016-06-13 18:56 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 [this message]
2016-06-14 1:32 ` Yong, Jonathan
2016-06-18 18:15 ` Bjorn Helgaas
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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