From: Oliver Neukum <oneukum@suse.com>
To: Thierry Reding <thierry.reding@gmail.com>,
"Rafael J. Wysocki" <rafael@kernel.org>
Cc: linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-tegra@vger.kernel.org
Subject: Re: Forcing devices into idle
Date: Thu, 3 Jul 2025 12:33:33 +0200 [thread overview]
Message-ID: <fbfc6bf9-d7c6-4df5-85d0-b1d357159d88@suse.com> (raw)
In-Reply-To: <rlzpjdsg6cbgxc553j6m25ysb6tyldy4lnxsjjn4hdzv7rszpp@y6rfcrbjfook>
On 03.07.25 12:08, Thierry Reding wrote:
> Any thoughts on how to solve this? Is the pm_runtime_{put,get}_sync()
> method acceptable? If not, are there other alternatives to achieve the
> same thing that I'm not aware of? Would it be useful to add a new set of
> APIs to force devices into an idle state (which could be semantically
> different from runtime suspend)? Or is this all too specific for any
> kind of generic API?
Basically what you need is what happens when the system prepares to
do a snapshot for S4. However, if you just perform FREEZE and then THAW,
devices will assume that user space has been frozen. You need a way
to substitute for that assumption.
Runtime power management is unlikely to be a fruitful approach to your
needs.
HTH
Oliver
next prev parent reply other threads:[~2025-07-03 10:33 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-03 10:08 Forcing devices into idle Thierry Reding
2025-07-03 10:33 ` Oliver Neukum [this message]
2025-07-03 11:12 ` Rafael J. Wysocki
2025-07-03 12:06 ` Thierry Reding
2025-07-03 13:32 ` Thierry Reding
2025-07-03 13:46 ` Rafael J. Wysocki
2025-07-03 14:14 ` Thierry Reding
2025-07-03 14:22 ` Rafael J. Wysocki
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