Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755025AbbFEQJo (ORCPT ); Fri, 5 Jun 2015 12:09:44 -0400 Received: from gloria.sntech.de ([95.129.55.99]:53737 "EHLO gloria.sntech.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754544AbbFEQJn (ORCPT ); Fri, 5 Jun 2015 12:09:43 -0400 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Caesar Wang Cc: dianders@chromium.org, Dmitry Torokhov , linux-rockchip@lists.infradead.org, Russell King , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 1/3] ARM: rockchip: fix the CPU soft reset Date: Fri, 05 Jun 2015 17:52:48 +0200 Message-ID: <1744325.yNd0r8SV4R@diego> User-Agent: KMail/4.14.1 (Linux/3.16.0-4-amd64; KDE/4.14.2; x86_64; ; ) In-Reply-To: <1433517104-7595-2-git-send-email-wxt@rock-chips.com> References: <1433517104-7595-1-git-send-email-wxt@rock-chips.com> <1433517104-7595-2-git-send-email-wxt@rock-chips.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3332 Lines: 105 Hi Caesar, Am Freitag, 5. Juni 2015, 23:11:42 schrieb Caesar Wang: > 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 > --- could we do this something like the shown below instead? Here the deassertion of the reset really happens after we are sure the power-domain is on -------------- 8< --------------- diff --git a/arch/arm/mach-rockchip/platsmp.c b/arch/arm/mach-rockchip/platsmp.c index 5b4ca3c..ee5dbad6 100644 --- a/arch/arm/mach-rockchip/platsmp.c +++ b/arch/arm/mach-rockchip/platsmp.c @@ -72,6 +72,7 @@ static struct reset_control *rockchip_get_core_reset(int cpu) static int pmu_set_power_domain(int pd, bool on) { u32 val = (on) ? 0 : BIT(pd); + struct reset_control *rstc = rockchip_get_core_reset(pd); int ret; /* @@ -80,20 +81,16 @@ static int pmu_set_power_domain(int pd, bool on) * processor is powered down. */ if (read_cpuid_part() != ARM_CPU_PART_CORTEX_A9) { - struct reset_control *rstc = rockchip_get_core_reset(pd); - + /* We only require the reset on the RK3288 at the moment */ if (IS_ERR(rstc)) { pr_err("%s: could not get reset control for core %d\n", __func__, pd); 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); @@ -112,6 +109,12 @@ static int pmu_set_power_domain(int pd, bool on) } } + if (read_cpuid_part() != ARM_CPU_PART_CORTEX_A9 && on) + reset_control_deassert(rstc); + + if (!IS_ERR(rstc)) + reset_control_put(rstc); + return 0; } -------------- 8< --------------- -- 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/