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From: Brian Norris <briannorris@chromium.org>
To: Bjorn Helgaas <bhelgaas@google.com>
Cc: "Lukas Wunner" <lukas@wunner.de>,
	linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
	linux-pm@vger.kernel.org,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	"Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Subject: Re: [PATCH v4] PCI/PM: Prevent runtime suspend before devices are fully initialized
Date: Tue, 25 Nov 2025 08:14:39 -0800	[thread overview]
Message-ID: <aSXV7y49lgA1cWmE@google.com> (raw)
In-Reply-To: <20251023140901.v4.1.I60a53c170a8596661883bd2b4ef475155c7aa72b@changeid>

Hi Bjorn,

On Thu, Oct 23, 2025 at 02:09:01PM -0700, Brian Norris wrote:
> Today, it's possible for a PCI device to be created and
> runtime-suspended before it is fully initialized. When that happens, the
> device will remain in D0, but the suspend process may save an
> intermediate version of that device's state -- for example, without
> appropriate BAR configuration. When the device later resumes, we'll
> restore invalid PCI state and the device may not function.
> 
> Prevent runtime suspend for PCI devices by deferring pm_runtime_enable()
> until we've fully initialized the device.
[...] 
> Link: https://lore.kernel.org/all/20251016155335.1.I60a53c170a8596661883bd2b4ef475155c7aa72b@changeid/
> Signed-off-by: Brian Norris <briannorris@chromium.org>
> Cc: <stable@vger.kernel.org>
> Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
> ---
> 
> Changes in v4:
>  * Move pm_runtime_set_active() too
> 
> Changes in v3:
>  * Add Link to initial discussion
>  * Add Rafael's Reviewed-by
>  * Add lengthier footnotes about forbid vs allow vs sysfs
> 
> Changes in v2:
>  * Update CC list
>  * Rework problem description
>  * Update solution: defer pm_runtime_enable(), instead of trying to
>    get()/put()
> 
>  drivers/pci/bus.c | 4 ++++
>  drivers/pci/pci.c | 2 --
>  2 files changed, 4 insertions(+), 2 deletions(-)

I'm wondering what the status of this patch is, as the next merge window
is approaching. It fixes a critical bug for me, and it has had plenty of
review.

Thanks,
Brian

  reply	other threads:[~2025-11-25 16:14 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-23 21:09 [PATCH v4] PCI/PM: Prevent runtime suspend before devices are fully initialized Brian Norris
2025-11-25 16:14 ` Brian Norris [this message]
2026-01-06 22:27 ` Bjorn Helgaas
2026-01-14  9:46   ` Marek Szyprowski
2026-01-14 16:45     ` Bjorn Helgaas
2026-01-14 20:10     ` Brian Norris
2026-01-15 11:14       ` Marek Szyprowski
2026-01-17  1:19         ` Brian Norris
2026-01-18 11:53           ` Rafael J. Wysocki
2026-01-18 11:59             ` Rafael J. Wysocki
2026-01-19 10:00               ` Marek Szyprowski
2026-01-19 12:26                 ` Rafael J. Wysocki
2026-01-19 13:13                   ` Marek Szyprowski
2026-01-19 16:10                     ` Rafael J. Wysocki
2026-01-22 17:49             ` Brian Norris

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