Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754757AbbFEPMw (ORCPT ); Fri, 5 Jun 2015 11:12:52 -0400 Received: from mail-pa0-f50.google.com ([209.85.220.50]:34903 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751474AbbFEPMs (ORCPT ); Fri, 5 Jun 2015 11:12:48 -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 v3 1/3] ARM: rockchip: fix the CPU soft reset Date: Fri, 5 Jun 2015 23:11:42 +0800 Message-Id: <1433517104-7595-2-git-send-email-wxt@rock-chips.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1433517104-7595-1-git-send-email-wxt@rock-chips.com> References: <1433517104-7595-1-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: 2836 Lines: 91 We need different orderings when turning a core on and turning a core off. In one case we need to assert reset before turning power off. In ther other case we need to turn power on and the deassert reset. In general, the correct flow is: CPU off: reset_control_assert regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), BIT(pd)) CPU on: regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), 0) reset_control_deassert This is needed for stressing CPU up/down, as per: cd /sys/devices/system/cpu/ for i in $(seq 1000); do echo "================= $i ============" for j in $(seq 100); do while [[ "$(cat cpu1/online)$(cat cpu2/online)$(cat cpu3/online)" != "000"" ]] echo 0 > cpu1/online echo 0 > cpu2/online echo 0 > cpu3/online done while [[ "$(cat cpu1/online)$(cat cpu2/online)$(cat cpu3/online)" != "111" ]]; do echo 1 > cpu1/online echo 1 > cpu2/online echo 1 > cpu3/online done done done The following is reproducile log: [34466.186812] PM: noirq suspend of devices complete after 0.669 msecs [34466.186824] Disabling non-boot CPUs ... [34466.187509] CPU1: shutdown [34466.188672] CPU2: shutdown [34473.736627] Kernel panic - not syncing:Watchdog detected hard LOCKUP on cpu 0 ....... Signed-off-by: Caesar Wang --- arch/arm/mach-rockchip/platsmp.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/arch/arm/mach-rockchip/platsmp.c b/arch/arm/mach-rockchip/platsmp.c index 5b4ca3c..25da16f 100644 --- a/arch/arm/mach-rockchip/platsmp.c +++ b/arch/arm/mach-rockchip/platsmp.c @@ -88,18 +88,24 @@ static int pmu_set_power_domain(int pd, bool on) return PTR_ERR(rstc); } - if (on) - reset_control_deassert(rstc); - else + if (!on) reset_control_assert(rstc); - reset_control_put(rstc); - } + ret = regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), val); + if (ret < 0) { + pr_err("%s: could not update power domain\n", __func__); + reset_control_put(rstc); + return ret; + } - ret = regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), val); - if (ret < 0) { - pr_err("%s: could not update power domain\n", __func__); - return ret; + if (on) + reset_control_deassert(rstc); + } else { + ret = regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), val); + if (ret < 0) { + pr_err("%s: could not update power domain\n", __func__); + return ret; + } } ret = -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/