linux-kernel - Re: [PATCH v3] PM / core: conditionally skip system pm in device/driver model

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date: Fri, 23 Feb 2024 18:43:51 +0100
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Guan-Yu Lin <guanyulin@...gle.com>
Cc: rafael@...nel.org, pavel@....cz, len.brown@...el.com, 
	gregkh@...uxfoundation.org, andriy.shevchenko@...ux.intel.com, 
	petr.tesarik.ext@...wei.com, rdunlap@...radead.org, james@...iv.tech, 
	broonie@...nel.org, james.clark@....com, masahiroy@...nel.org, 
	linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org
Subject: Re: [PATCH v3] PM / core: conditionally skip system pm in
 device/driver model

On Fri, Feb 23, 2024 at 3:38 PM Guan-Yu Lin <guanyulin@...gle.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@...gle.com>

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