linux-kernel - Re: [PATCH v2] clocksource: sp804: Make user selectable

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: <11c5de84-21f0-45de-81e0-dc765a391123@linaro.org>
Date: Tue, 9 Jul 2024 18:15:40 +0200
From: Daniel Lezcano <daniel.lezcano@...aro.org>
To: Mark Brown <broonie@...nel.org>
Cc: Thomas Gleixner <tglx@...utronix.de>,
 David Abdurachmanov <david.abdurachmanov@...il.com>,
 Sudeep Holla <sudeep.holla@....com>, linux-arm-kernel@...ts.infradead.org,
 linux-kernel@...r.kernel.org, Ross Burton <ross.burton@....com>
Subject: Re: [PATCH v2] clocksource: sp804: Make user selectable

On 08/07/2024 19:44, Mark Brown wrote:
> On Mon, Jul 08, 2024 at 06:49:38PM +0200, Daniel Lezcano wrote:
>> On 29/05/2024 21:48, Mark Brown wrote:
> 
>>> The sp804 is currently only user selectable if COMPILE_TEST, this was
>>> done by commit dfc82faad725 ("clocksource/drivers/sp804: Add
>>> COMPILE_TEST to CONFIG_ARM_TIMER_SP804") in order to avoid it being
>>> spuriously offered on platforms that won't have the hardware since it's
>>> generally only seen on Arm based platforms.  This config is overly
>>> restrictive, while platforms that rely on the SP804 do select it in
>>> their Kconfig there are others such as the Arm fast models which have a
>>> SP804 available but currently unused by Linux.  Relax the dependency to
>>> allow it to be user selectable on arm and arm64 to avoid surprises and
>>> in case someone comes up with a use for extra timer hardware.
> 
>> Would it make sense to add the option in the platform so it selects the
>> timer ?
> 
> As the commit log says far as I'm aware all the platforms that rely on
> the sp804 timer already select it (they wouldn't otherwise be able to
> work unless COMPILE_TEST was enabled).  The Arm models and possibly
> other platforms have the sp804 but it will currently be ignored by Linux
> and the architected timers used instead so it would be wasteful to force
> it on for them.

The policy of the Kconfig is we should keep the option silent.

My suggestion was to provide the option in the platforms Kconfig and 
[un]select the ARM_TIMER_SP804 from there


-- 
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog