Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933017AbbFIJuj (ORCPT ); Tue, 9 Jun 2015 05:50:39 -0400 Received: from mail-pa0-f43.google.com ([209.85.220.43]:33911 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932767AbbFIJuS (ORCPT ); Tue, 9 Jun 2015 05:50:18 -0400 From: Caesar Wang To: Heiko Stuebner Cc: dianders@chromium.org, Dmitry Torokhov , linux-rockchip@lists.infradead.org, Caesar Wang , Russell King , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v6 2/3] ARM: rockchip: ensure CPU to enter WFI/WFE state Date: Tue, 9 Jun 2015 17:49:58 +0800 Message-Id: <1433843400-24831-3-git-send-email-wxt@rock-chips.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1433843400-24831-1-git-send-email-wxt@rock-chips.com> References: <1433843400-24831-1-git-send-email-wxt@rock-chips.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1508 Lines: 48 The patch can ensure that v7_exit_coherency_flush() in rockchip_cpu_die() executed in time. The mdelay(1) has enough time to fix the problem of CPU offlining. That's a workaround way in rockchip hotplug code, At least, we haven't a better way to solve it. Who know, that maybe fixed by chip (hardware) in the future. Signed-off-by: Caesar Wang --- Changes in v6: - Fix the delay 1ms describing. Series-changes: 5 - Fix the patch decription. - Add the changelog. Series-changes: 2 - As Kever points out, Fix the subject typo WFI/WFE. arch/arm/mach-rockchip/platsmp.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/arm/mach-rockchip/platsmp.c b/arch/arm/mach-rockchip/platsmp.c index b379cc8..d629206 100644 --- a/arch/arm/mach-rockchip/platsmp.c +++ b/arch/arm/mach-rockchip/platsmp.c @@ -322,6 +322,13 @@ static void __init rockchip_smp_prepare_cpus(unsigned int max_cpus) #ifdef CONFIG_HOTPLUG_CPU static int rockchip_cpu_kill(unsigned int cpu) { + /* + * We need a delay here to ensure that the dying CPU can finish + * executing v7_coherency_exit() and reach the WFI/WFE state + * prior to having the power domain disabled. + */ + mdelay(1); + pmu_set_power_domain(0 + cpu, false); return 1; } -- 1.9.1 -- 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/