Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422640AbbFEQ2p (ORCPT ); Fri, 5 Jun 2015 12:28:45 -0400 Received: from mail-ig0-f181.google.com ([209.85.213.181]:35387 "EHLO mail-ig0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752273AbbFEQ2n (ORCPT ); Fri, 5 Jun 2015 12:28:43 -0400 MIME-Version: 1.0 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> Date: Fri, 5 Jun 2015 09:28:42 -0700 X-Google-Sender-Auth: ZOdXEX7_tI4cm94V1AVgcNuR7sY Message-ID: Subject: Re: [PATCH v3 1/3] ARM: rockchip: fix the CPU soft reset From: Doug Anderson To: Caesar Wang Cc: Heiko Stuebner , Dmitry Torokhov , "open list:ARM/Rockchip SoC..." , Russell King , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@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: 2212 Lines: 63 Caesar, On Fri, Jun 5, 2015 at 8:11 AM, Caesar Wang wrote: > 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)) Add: "ensure power domain is on" to this list. > CPU on: > regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), 0) > reset_control_deassert Add: "ensure power domain is on" to this list. Adding the "ensure power domain is on" step helps document that patch set version 2 is not what you want and that you thought about it. > @@ -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); I think you need a "reset_control_put(rstc);" here in the non-error case. Otherwise this looks reasonable to me and you can add my Reviewed-by tag. I'll also kick off some tests with this series today to confirm as well. -Doug -- 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/