From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754705AbaIBPzd (ORCPT ); Tue, 2 Sep 2014 11:55:33 -0400 Received: from mail-oi0-f43.google.com ([209.85.218.43]:58681 "EHLO mail-oi0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754037AbaIBPzc (ORCPT ); Tue, 2 Sep 2014 11:55:32 -0400 MIME-Version: 1.0 In-Reply-To: References: Date: Tue, 2 Sep 2014 11:55:31 -0400 X-Google-Sender-Auth: nZICOPLbcSBuejwDUl-9nXnL1Ww Message-ID: Subject: Re: [PATCH] Revert "leds: convert blink timer to workqueue" From: Josh Boyer To: Jiri Kosina Cc: Vincent Donnefort , Bryan Wu , Linus Torvalds , Hugh Dickins , Tejun Heo , "Linux-Kernel@Vger. Kernel. Org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 2, 2014 at 5:03 AM, Jiri Kosina wrote: > This reverts commit 8b37e1bef5a6b60e949e28a4db3006e4b00bd758. > > It's broken as it changes led_blink_set() in a way that it can now sleep > (while synchronously waiting for workqueue to be cancelled). That's a > problem, because it's possible that this function gets called from atomic > context (tpt_trig_timer() takes a readlock and thus disables preemption). > > This has been brought up 3 weeks ago already [1] but no proper fix has > materialized, and I keep seeing the problem since 3.18-rc1. > > [1] https://lkml.org/lkml/2014/8/16/128 FWIW we're seeing it reported in Fedora too. Perhaps a revert is the right approach for now. josh