Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932296AbbLNLC6 (ORCPT ); Mon, 14 Dec 2015 06:02:58 -0500 Received: from mail-qk0-f169.google.com ([209.85.220.169]:36718 "EHLO mail-qk0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932176AbbLNLC4 (ORCPT ); Mon, 14 Dec 2015 06:02:56 -0500 MIME-Version: 1.0 In-Reply-To: <1449844798-27384-1-git-send-email-m.szyprowski@samsung.com> References: <1449844798-27384-1-git-send-email-m.szyprowski@samsung.com> Date: Mon, 14 Dec 2015 20:02:54 +0900 Message-ID: Subject: Re: [PATCH] clk: exynos: use irqsave version of spin_lock to avoid deadlock with irqs From: Tomasz Figa To: Marek Szyprowski Cc: "linux-samsung-soc@vger.kernel.org" , linux-kernel , "linux-pm@vger.kernel.org" , Sylwester Nawrocki , Mike Turquette , Krzysztof Kozlowski , Bartlomiej Zolnierkiewicz , Viresh Kumar , Thomas Abraham , Ben Gamari , Lukasz Majewski , Chanwoo Choi , Kevin Hilman , stable@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 834 Lines: 22 Hi Marek, 2015-12-11 23:38 GMT+09:00 Marek Szyprowski : > It is allowed to enable/disable clocks from interrupts, so common Exynos > ARM clock management code for CPUfreq should use 'irqsave' version of > spin_lock calls to avoid potential deadlock caused by spin_lock recursion. > The same spin_lock is used by gate/mux clocks during enable/disable calls. > > This deadlock, can be reproduced by enabling CPUfreq (ondemand or > userspace) and decoding video with s5p-mfc driver. Good catch. Acked-by: Tomasz Figa Best regards, Tomasz -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/