From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0DA1FECDE4C for ; Thu, 8 Nov 2018 21:56:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C9FED21019 for ; Thu, 8 Nov 2018 21:56:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Ck8+O/DS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C9FED21019 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729104AbeKIHdo (ORCPT ); Fri, 9 Nov 2018 02:33:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:49744 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729035AbeKIHdn (ORCPT ); Fri, 9 Nov 2018 02:33:43 -0500 Received: from localhost (unknown [208.72.13.198]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 09EB921479; Thu, 8 Nov 2018 21:56:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541714175; bh=jeSS1fh388oTuNBSX4IRZnmetc6p+5YOgSMUnQo90bg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ck8+O/DSORx4LLXVRiqoAplF54WJwL0I/HpYFnd/cYDzo902Ym/GtzctC+a5WfZEL WRFDzBRPFHw7+GPZMCRY152gy2agEVusPMJwEUclAlM9mAEBtQoKhUjCPdNzyqzdyP Ih+yYsnZCE1SvJkwHGLqnNdsrJbSsGdmyconjSxI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Heiko Stuebner , Doug Anderson , Michael Turquette , Sasha Levin Subject: [PATCH 3.18 080/144] clk: rockchip: fix deadlock possibility in cpuclk Date: Thu, 8 Nov 2018 13:50:51 -0800 Message-Id: <20181108215101.127234986@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181108215054.826084593@linuxfoundation.org> References: <20181108215054.826084593@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit a5e1baf7dca10f8cf945394034013260297bc416 ] Lockdep reported a possible deadlock between the cpuclk lock and for example the i2c driver. CPU0 CPU1 ---- ---- lock(clk_lock); local_irq_disable(); lock(&(&i2c->lock)->rlock); lock(clk_lock); lock(&(&i2c->lock)->rlock); *** DEADLOCK *** The generic clock-types of the core ccf already use spin_lock_irqsave when touching clock registers, so do the same for the cpuclk. Signed-off-by: Heiko Stuebner Reviewed-by: Doug Anderson Signed-off-by: Michael Turquette [mturquette@linaro.org: removed initialization of "flags"] Signed-off-by: Sasha Levin --- drivers/clk/rockchip/clk-cpu.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/clk/rockchip/clk-cpu.c b/drivers/clk/rockchip/clk-cpu.c index 75c8c45ef728..8539c4fd34cc 100644 --- a/drivers/clk/rockchip/clk-cpu.c +++ b/drivers/clk/rockchip/clk-cpu.c @@ -124,10 +124,11 @@ static int rockchip_cpuclk_pre_rate_change(struct rockchip_cpuclk *cpuclk, { const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data; unsigned long alt_prate, alt_div; + unsigned long flags; alt_prate = clk_get_rate(cpuclk->alt_parent); - spin_lock(cpuclk->lock); + spin_lock_irqsave(cpuclk->lock, flags); /* * If the old parent clock speed is less than the clock speed @@ -164,7 +165,7 @@ static int rockchip_cpuclk_pre_rate_change(struct rockchip_cpuclk *cpuclk, cpuclk->reg_base + reg_data->core_reg); } - spin_unlock(cpuclk->lock); + spin_unlock_irqrestore(cpuclk->lock, flags); return 0; } @@ -173,6 +174,7 @@ static int rockchip_cpuclk_post_rate_change(struct rockchip_cpuclk *cpuclk, { const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data; const struct rockchip_cpuclk_rate_table *rate; + unsigned long flags; rate = rockchip_get_cpuclk_settings(cpuclk, ndata->new_rate); if (!rate) { @@ -181,7 +183,7 @@ static int rockchip_cpuclk_post_rate_change(struct rockchip_cpuclk *cpuclk, return -EINVAL; } - spin_lock(cpuclk->lock); + spin_lock_irqsave(cpuclk->lock, flags); if (ndata->old_rate < ndata->new_rate) rockchip_cpuclk_set_dividers(cpuclk, rate); @@ -201,7 +203,7 @@ static int rockchip_cpuclk_post_rate_change(struct rockchip_cpuclk *cpuclk, if (ndata->old_rate > ndata->new_rate) rockchip_cpuclk_set_dividers(cpuclk, rate); - spin_unlock(cpuclk->lock); + spin_unlock_irqrestore(cpuclk->lock, flags); return 0; } -- 2.17.1