linux-pci.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: Bjorn Helgaas <bhelgaas@google.com>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Lukas Wunner <lukas@wunner.de>, David Airlie <airlied@linux.ie>,
	Daniel Vetter <daniel@ffwll.ch>,
	Utkarsh Patel <utkarsh.h.patel@intel.com>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	linux-pci@vger.kernel.org
Subject: Re: [PATCH] PCI/PM: Do not generate wakeup event when runtime resuming bus
Date: Fri, 13 Nov 2020 08:37:45 +0200	[thread overview]
Message-ID: <20201113063745.GH2495@lahna.fi.intel.com> (raw)
In-Reply-To: <20201029092453.69869-1-mika.westerberg@linux.intel.com>

Hi,

On Thu, Oct 29, 2020 at 12:24:53PM +0300, Mika Westerberg wrote:
> When a PCI bridge is runtime resumed from D3cold the underlying bus is
> walked and the attached devices are runtime resumed as well. However, in
> addition to that we also generate a wakeup event for these devices even
> though this actually is not a real wakeup event coming from the
> hardware.
> 
> Normally this does not cause problems but when combined with
> /sys/power/wakeup_count like using the steps below:
> 
>   # count=$(cat /sys/power/wakeup_count)
>   # echo $count > /sys/power/wakeup_count
>   # echo mem > /sys/power/state
> 
> The system suspend cycle might get aborted at this point if a PCI bridge
> that was runtime suspended (D3cold) was runtime resumed for any reason.
> The runtime resume calls pci_wakeup_bus() and that generates wakeup
> event increasing wakeup_count.
> 
> Since this is not a real wakeup event we can prevent the above from
> happening by removing the call to pci_wakeup_event() in
> pci_wakeup_bus(). While there rename pci_wakeup_bus() to
> pci_resume_bus() to better reflect what it does.

Any comments on this?

Thanks!

  reply	other threads:[~2020-11-13  6:40 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-29  9:24 Mika Westerberg
2020-11-13  6:37 ` Mika Westerberg [this message]
2020-11-16 16:06   ` Rafael J. Wysocki
2020-11-16 16:05 ` Rafael J. Wysocki
2020-11-18 21:22 ` Bjorn Helgaas
2020-11-19  7:55   ` Mika Westerberg
2020-11-20  2:27     ` Patel, Utkarsh H

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=20201113063745.GH2495@lahna.fi.intel.com \
    --to=mika.westerberg@linux.intel.com \
    --cc=airlied@linux.ie \
    --cc=bhelgaas@google.com \
    --cc=daniel@ffwll.ch \
    --cc=linux-pci@vger.kernel.org \
    --cc=lukas@wunner.de \
    --cc=maarten.lankhorst@linux.intel.com \
    --cc=mripard@kernel.org \
    --cc=rjw@rjwysocki.net \
    --cc=tzimmermann@suse.de \
    --cc=utkarsh.h.patel@intel.com \
    --subject='Re: [PATCH] PCI/PM: Do not generate wakeup event when runtime resuming bus' \
    /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

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).