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From: "Rafael J. Wysocki" <rafael@kernel.org>
Date: Fri, 23 Feb 2024 18:43:51 +0100
Message-ID: <CAJZ5v0gM=0rU6a1A6Bh2Ed=4=1AtQ3p5aDJVCOioA6qxGv1jtQ@mail.gmail.com>
Subject: Re: [PATCH v3] PM / core: conditionally skip system pm in
 device/driver model
To: Guan-Yu Lin <guanyulin@google.com>
Cc: rafael@kernel.org, pavel@ucw.cz, len.brown@intel.com, 
	gregkh@linuxfoundation.org, andriy.shevchenko@linux.intel.com, 
	petr.tesarik.ext@huawei.com, rdunlap@infradead.org, james@equiv.tech, 
	broonie@kernel.org, james.clark@arm.com, masahiroy@kernel.org, 
	linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org
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On Fri, Feb 23, 2024 at 3:38=E2=80=AFPM Guan-Yu Lin <guanyulin@google.com> =
wrote:
>
> In systems with a main processor and a co-processor, asynchronous
> controller management can lead to conflicts.  One example is the main
> processor attempting to suspend a device while the co-processor is
> actively using it. To address this, we introduce a new sysfs entry
> called "conditional_skip". This entry allows the system to selectively
> skip certain device power management state transitions. To use this
> feature, set the value in "conditional_skip" to indicate the type of
> state transition you want to avoid.  Please review /Documentation/ABI/
> testing/sysfs-devices-power for more detailed information.
>
> Signed-off-by: Guan-Yu Lin <guanyulin@google.com>

Please explain how this is intended to work.  That is, what exactly
you expect to happen when the new attribute is set.