linux-kernel - Re: [PATCH v1] ASoC: meson: axg-fifo: set option to use raw spinlock

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: <1j5xsow839.fsf@starbuckisacylon.baylibre.com>
Date: Mon, 29 Jul 2024 17:06:50 +0200
From: Jerome Brunet <jbrunet@...libre.com>
To: Mark Brown <broonie@...nel.org>
Cc: Arseniy Krasnov <avkrasnov@...utedevices.com>,  Liam Girdwood
 <lgirdwood@...il.com>,  Jaroslav Kysela <perex@...ex.cz>,  Takashi Iwai
 <tiwai@...e.com>,  Neil Armstrong <neil.armstrong@...aro.org>,  Kevin
 Hilman <khilman@...libre.com>,  Martin Blumenstingl
 <martin.blumenstingl@...glemail.com>,  alsa-devel@...a-project.org,
  linux-sound@...r.kernel.org,  linux-arm-kernel@...ts.infradead.org,
  linux-amlogic@...ts.infradead.org,  linux-kernel@...r.kernel.org,
  kernel@...rdevices.ru,  oxffffaa@...il.com
Subject: Re: [PATCH v1] ASoC: meson: axg-fifo: set option to use raw spinlock

On Mon 29 Jul 2024 at 15:44, Mark Brown <broonie@...nel.org> wrote:

> On Mon, Jul 29, 2024 at 04:15:31PM +0200, Jerome Brunet wrote:
>
>> Maybe mmio regmap should '.use_raw_spinlock = true' by default when
>> '.fast_io' is set ?
>
>> Mark, what is your opinion on this ? I guess it is not the first time
>> this occurs ?
>
> I don't recall this coming up much TBH.  It may be that people just set
> raw spinlocks when they need it, or that there's not many people using
> relevant devices with RT kernels.

I have not been playing much with RT TBH, but AFAIK, with RT irq
handlers are threaded unless IRQF_NO_THREAD is set. In this case,
something preemptible in the handler should not be a problem.

The axg-fifo drivers do not have IRQF_NO_THREAD so something is a bit
unclear here.

-- 
Jerome