public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Bjorn Helgaas <helgaas@kernel.org>
To: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Cc: Jian-Hong Pan <jhp@endlessos.org>,
	Johan Hovold <johan@kernel.org>,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	David Box <david.e.box@linux.intel.com>,
	Damien Le Moal <dlemoal@kernel.org>,
	Niklas Cassel <cassel@kernel.org>,
	Nirmal Patel <nirmal.patel@linux.intel.com>,
	Jonathan Derrick <jonathan.derrick@linux.dev>,
	linux-pci@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
	linux@endlessos.org
Subject: Re: [PATCH v2] PCI: vmd: Enable PCI PM's L1 substates of remapped PCIe Root Port and NVMe
Date: Tue, 6 Feb 2024 10:00:57 -0600	[thread overview]
Message-ID: <20240206160057.GA866439@bhelgaas> (raw)
In-Reply-To: <72b9ef46-851b-3555-0a43-8da4d4ab0fad@linux.intel.com>

On Tue, Feb 06, 2024 at 02:29:12PM +0200, Ilpo Järvinen wrote:
> On Fri, 2 Feb 2024, Jian-Hong Pan wrote:
> ...

> > +out_enable_link_state:
> > +	/*
> > +	 * Make PCI devices at D0 when enable PCI-PM L1 PM Substates from
> > +	 * Section 5.5.4 of PCIe Base Spec Revision 6.0
> 
> I don't understand what are you trying to say here? Are there some typos 
> or grammar errors or something entire missing from the comment?

This is about the fact that per sec 5.5.4, "If setting either or both
of the enable bits for PCI-PM L1 PM Substates, both ports must be
configured as described in this section while in D0."

We can wordsmith this a little, maybe:

  Ensure devices are in D0 before enabling PCI-PM L1 PM Substates, per
  PCIe r6.0, sec 5.5.4.

I look a little askance at having to do this separately from
pci_enable_link_state_locked(), but we can solve that elsewhere if
need be.

> > +	pci_set_power_state_locked(pdev, PCI_D0);
> > +	pci_enable_link_state_locked(pdev, PCIE_LINK_STATE_ALL);

      reply	other threads:[~2024-02-06 16:00 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-02-02  7:11 [PATCH v2] PCI: vmd: Enable PCI PM's L1 substates of remapped PCIe Root Port and NVMe Jian-Hong Pan
2024-02-03  0:05 ` Bjorn Helgaas
2024-02-05 19:37   ` David E. Box
2024-02-05 22:42     ` Bjorn Helgaas
2024-02-05 23:05       ` David E. Box
2024-02-06 21:25         ` David E. Box
2024-02-06 23:30           ` Bjorn Helgaas
2024-02-07 19:51             ` David E. Box
2024-02-06 12:29 ` Ilpo Järvinen
2024-02-06 16:00   ` Bjorn Helgaas [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20240206160057.GA866439@bhelgaas \
    --to=helgaas@kernel.org \
    --cc=cassel@kernel.org \
    --cc=david.e.box@linux.intel.com \
    --cc=dlemoal@kernel.org \
    --cc=ilpo.jarvinen@linux.intel.com \
    --cc=jhp@endlessos.org \
    --cc=johan@kernel.org \
    --cc=jonathan.derrick@linux.dev \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=linux@endlessos.org \
    --cc=mika.westerberg@linux.intel.com \
    --cc=nirmal.patel@linux.intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox