linux-kernel - Re: [PATCH] counter: add COUNTER_FUNCTION

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 for Android: free password hash cracker in your pocket

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

Message-ID: <Z0eAg9HRlYlCy25H@ishi>
Date: Thu, 28 Nov 2024 05:26:43 +0900
From: William Breathitt Gray <wbg@...nel.org>
To: "Rafael V. Volkmer" <rafael.v.volkmer@...il.com>
Cc: david@...hnology.com, linux-kernel@...r.kernel.org,
	linux-iio@...r.kernel.org
Subject: Re: [PATCH] counter: add COUNTER_FUNCTION_DISABLE for energy saving

On Mon, Nov 25, 2024 at 08:02:20PM -0300, Rafael V. Volkmer wrote:
> Add `COUNTER_FUNCTION_DISABLE` to the `counter_function` enum in the
> counter API. This allows file operations to signal other drivers to
> disable hardware resources, reducing energy consumption in
> power-sensitive scenarios.
> 
> Previously, tests with Texas Instruments' eQEP modules revealed that
> hardware resources remained active unless the driver was removed,
> offering no user command to stop the count. This approach exposed the
> fragility of these resources.
> 
> To address this, introduce a new enum option in the counter API to
> receive commands for disabling the hardware. This ensures the hardware
> enters an idle, power-saving state when not in use.
> 
> Signed-off-by: Rafael V. Volkmer <rafael.v.volkmer@...il.com>

Hello Rafael,

I wonder whether a new enum option is actually needed in this case.
Wouldn't the Count "enable" extension already provide a way for users to
stop the counting? I imagine the driver would determine implicitly that
the device can enter a power-saving state in that scenario when counting
has been disabled by the user.

William Breathitt Gray

Download attachment "signature.asc" of type "application/pgp-signature" (229 bytes)