Linux LED subsystem development
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From: Johannes Berg <johannes@sipsolutions.net>
To: Pavel Machek <pavel@ucw.cz>
Cc: linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Subject: Re: [PATCH] leds: trigger: use RCU to protect the led_cdevs list
Date: Mon, 27 Sep 2021 16:20:47 +0200	[thread overview]
Message-ID: <97300681a8e793b71ccedf8224010f1f64da6b5c.camel@sipsolutions.net> (raw)
In-Reply-To: <20210927141619.GA18276@duo.ucw.cz>

Hi Pavel,

> > 
> > Cc: stable@vger.kernel.org
> 
> I ... don't like idea of this going to stable.

OK, I guess that's fair. We've been running into the lockdep report for
a while - ever since we made the spinlock in iwlwifi no longer disable
IRQs all the time, which was meant to be a good thing ...

However, the scenario that could cause *real* deadlocks there is really
unlikely and requires four CPUs all doing the exactly right thing,
including a normally very rare *write lock* on the leddev_list_lock, so
I don't think in practice it'll be much of an issue.

johannes




      reply	other threads:[~2021-09-27 14:20 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-15 16:16 [PATCH] leds: trigger: use RCU to protect the led_cdevs list Johannes Berg
2021-09-27 14:16 ` Pavel Machek
2021-09-27 14:20   ` Johannes Berg [this message]

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