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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Pavel Machek <pavel@ucw.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	johannes.berg@intel.com, linux-leds@vger.kernel.org
Subject: Re: [PATCH] leds: trigger: Disable CPU trigger on PREEMPT_RT
Date: Mon, 27 Sep 2021 19:18:02 +0200	[thread overview]
Message-ID: <20210927171802.uak3tbpqaig3mm7m@linutronix.de> (raw)
In-Reply-To: <20210927154451.GA17112@duo.ucw.cz>

On 2021-09-27 17:44:51 [+0200], Pavel Machek wrote:
> 
> Would you mind reading and responding to the rest of the email?

The patch you mentioned,
  https://https://lkml.kernel.org/r/.kernel.org/all/20210915181601.99a68f5718be.I1a28b342d2d52cdeeeb81ecd6020c25cbf1dbfc0@changeid/

would remove the lock from led_trigger_event().
Are there any guarantees how many callbacks maybe invoked and what kind
of locks may be acquired?
Leaving kworker usage aside there are still things like spinlock_t usage
in input_leds_brightness_set(), nic78bx_brightness_set() (from a quick
grep) which have the same problems.

> I'm not applying this.

I hope you reconsider. It is not all LED usage, just the CPU trigger.

> 								Pavel

Sebastian

  reply	other threads:[~2021-09-27 17:20 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-24 11:15 [PATCH] leds: trigger: Disable CPU trigger on PREEMPT_RT Sebastian Andrzej Siewior
2021-09-27 14:23 ` Pavel Machek
2021-09-27 15:35   ` Thomas Gleixner
2021-09-27 15:44     ` Pavel Machek
2021-09-27 17:18       ` Sebastian Andrzej Siewior [this message]
2021-09-27 17:36         ` Johannes Berg
2021-09-27 19:06         ` Pavel Machek
2021-09-27 19:34           ` Sebastian Andrzej Siewior
2021-10-13  8:08             ` Pavel Machek
2021-10-13  8:39               ` Sebastian Andrzej Siewior
2021-10-13  8:42                 ` Pavel Machek
2021-10-13  9:08                   ` Sebastian Andrzej Siewior
2021-10-13  9:37                   ` [PATCH v2] " Sebastian Andrzej Siewior
2021-10-13 18:08                     ` Pavel Machek
2021-09-28  0:14           ` [PATCH] " Thomas Gleixner
2021-09-27 18:48       ` Thomas Gleixner

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