From: Michael Buesch <mb@bu3sch.de>
To: Johannes Berg <johannes@sipsolutions.net>
Subject: Re: b43 problem with led trigger registration
Date: Sun, 16 Dec 2007 21:26:56 +0100
Cc: linux-wireless <linux-wireless@vger.kernel.org>,
	Larry Finger <Larry.Finger@lwfinger.net>,
	Richard Purdie <rpurdie@openedhand.com>
References: <1197822019.4138.2.camel@johannes.berg> <200712162036.11084.mb@bu3sch.de> <1197835176.6769.21.camel@johannes.berg>
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On Sunday 16 December 2007 20:59:36 Johannes Berg wrote:
> 
> > I have no idea where we enter atomic state.
> 
> Uh huh...
> 
> drivers/leds/led-triggers.c:led_trigger_register:
> 
> |        read_lock(&leds_list_lock);
> |        list_for_each_entry(led_cdev, &leds_list, node) {
> |                down_write(&led_cdev->trigger_lock);
> 
> introduced in
> 
> commit dc47206e552c0850ad11f7e9a1fca0a3c92f5d65
> Author: Richard Purdie <rpurdie@rpsys.net>
> Date:   Sat Nov 10 13:29:04 2007 +0000
> 
>     leds: Fix led trigger locking bugs
> 
> I guess the read_lock needs to be a mutex/rw semaphore.

Uh, yes. Was this patch tested at all?

-- 
Greetings Michael.