From patchwork Wed Apr 29 05:58:39 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shawn Guo X-Patchwork-Id: 6293811 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id D307E9F373 for ; Wed, 29 Apr 2015 06:03:54 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C6EB02021F for ; Wed, 29 Apr 2015 06:03:53 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 99C1D20218 for ; Wed, 29 Apr 2015 06:03:52 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1YnL42-0000Iv-5J; Wed, 29 Apr 2015 06:01:42 +0000 Received: from mail-pa0-f53.google.com ([209.85.220.53]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YnL3y-0000HF-D7 for linux-arm-kernel@lists.infradead.org; Wed, 29 Apr 2015 06:01:39 +0000 Received: by pacwv17 with SMTP id wv17so18305736pac.0 for ; Tue, 28 Apr 2015 23:01:16 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=d6LxCWGpYuWC9r7QsMcUnX0jPwkD5uLv9Uv+gW/otz8=; b=VNDYwWSgRbotPVM4oDpkAmZGy/2Vi4TnOfvx1x9h988nyG2070O5OnxwN8oqS2N1f3 OiASj2Rla37BRkJUPBpDxObSZie8Fx7+mpwvwZ4S7i9lXfvkBSc4qE2dqFBZzGX/q9UJ 27KdOa10gob8cuXzDZhq+NtEuS0NDHmawnfBSKGmAxxcibZzEyvSktsWuj1mrzE+CPPn RKb2t3ekgxRrWxXjpFZ2gRnzkJK3IUsYoDezDk2nVpsanPrVDfOFw/YUy68YaVj8Wiqh 5Oqt+TP7rimxp00QTkoTkBZm1JVKGPTz3rXTWITGJiFGFoBm3TgSwdIDU1qWV+tUHFHP 3Tfw== X-Gm-Message-State: ALoCoQk3Ei7QICAkgg3lrwaWAosAwsUySRJXaOr+E4Vjvtt16x7zjBnAKErwI2uRvAMjzhgjufof X-Received: by 10.70.134.198 with SMTP id pm6mr39242225pdb.17.1430287276294; Tue, 28 Apr 2015 23:01:16 -0700 (PDT) Received: from localhost.localdomain ([104.207.83.1]) by mx.google.com with ESMTPSA id cd10sm24273977pac.7.2015.04.28.23.01.14 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 28 Apr 2015 23:01:15 -0700 (PDT) From: Shawn Guo To: linux-arm-kernel@lists.infradead.org Subject: [PATCH] ARM: imx6: initialize CCM_CLPCR_LPM into RUN mode earlier Date: Wed, 29 Apr 2015 13:58:39 +0800 Message-Id: <1430287119-5268-1-git-send-email-shawn.guo@linaro.org> X-Mailer: git-send-email 1.9.1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150428_230138_482129_5A20103C X-CRM114-Status: GOOD ( 16.37 ) X-Spam-Score: -0.9 (/) Cc: Shawn Guo , kernel@pengutronix.de X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Commit 4631960d26da ("ARM: imx6: set initial power mode in pm function") moves imx6_set_lpm() from clock init function into imx6_pm_common_init(). This causes a hang when cpuidle support is enabled. The reason for that is ARM core clock is shut down unexpectedly by WAIT mode. It happens with the following call stack: cpuidle_register_governor() cpuidle_switch_governor() cpuidle_uninstall_idle_handler() synchronize_sched() wait_rcu_gp() wait_for_completion() When wait_for_completion() is called as above, all cores are idle/WFI. Hence, the reset value of CCM_CLPCR_LPM - WAIT mode, will trigger a hardware shutdown of the ARM core clock. To fix the regression, we need to ensure that CCM_CLPCR_LPM is initialized into RUN mode earlier than cpuidle governor registration, which is a postcore_initcall. This patch creates function imx6_pm_ccm_init() to map CCM block and initialize CCM_CLPCR_LPM into RUN mode, and have the function called from machine .init_irq hook, which should be early enough. Reported-by: Kevin Hilman Fixes: 4631960d26da ("ARM: imx6: set initial power mode in pm function") Signed-off-by: Shawn Guo Tested-by: Tyler Baker --- arch/arm/mach-imx/common.h | 1 + arch/arm/mach-imx/mach-imx6q.c | 1 + arch/arm/mach-imx/mach-imx6sl.c | 1 + arch/arm/mach-imx/mach-imx6sx.c | 1 + arch/arm/mach-imx/pm-imx6.c | 28 ++++++++++++++++++---------- 5 files changed, 22 insertions(+), 10 deletions(-) diff --git a/arch/arm/mach-imx/common.h b/arch/arm/mach-imx/common.h index d1e2873f807e..fbd86f1b7f3b 100644 --- a/arch/arm/mach-imx/common.h +++ b/arch/arm/mach-imx/common.h @@ -123,6 +123,7 @@ static inline void v7_cpu_resume(void) {} static inline void imx6_suspend(void __iomem *ocram_vbase) {} #endif +void imx6_pm_ccm_init(const char *ccm_compat); void imx6q_pm_init(void); void imx6dl_pm_init(void); void imx6sl_pm_init(void); diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c index 3ab61549ce0f..9602cc12d2f1 100644 --- a/arch/arm/mach-imx/mach-imx6q.c +++ b/arch/arm/mach-imx/mach-imx6q.c @@ -393,6 +393,7 @@ static void __init imx6q_init_irq(void) imx_init_l2cache(); imx_src_init(); irqchip_init(); + imx6_pm_ccm_init("fsl,imx6q-ccm"); } static const char * const imx6q_dt_compat[] __initconst = { diff --git a/arch/arm/mach-imx/mach-imx6sl.c b/arch/arm/mach-imx/mach-imx6sl.c index 12a1b098fc6a..300326373166 100644 --- a/arch/arm/mach-imx/mach-imx6sl.c +++ b/arch/arm/mach-imx/mach-imx6sl.c @@ -66,6 +66,7 @@ static void __init imx6sl_init_irq(void) imx_init_l2cache(); imx_src_init(); irqchip_init(); + imx6_pm_ccm_init("fsl,imx6sl-ccm"); } static const char * const imx6sl_dt_compat[] __initconst = { diff --git a/arch/arm/mach-imx/mach-imx6sx.c b/arch/arm/mach-imx/mach-imx6sx.c index f17b7004c24b..6a0b0614de29 100644 --- a/arch/arm/mach-imx/mach-imx6sx.c +++ b/arch/arm/mach-imx/mach-imx6sx.c @@ -86,6 +86,7 @@ static void __init imx6sx_init_irq(void) imx_init_l2cache(); imx_src_init(); irqchip_init(); + imx6_pm_ccm_init("fsl,imx6sx-ccm"); } static void __init imx6sx_init_late(void) diff --git a/arch/arm/mach-imx/pm-imx6.c b/arch/arm/mach-imx/pm-imx6.c index 27bc80dab2d8..b01650d94f91 100644 --- a/arch/arm/mach-imx/pm-imx6.c +++ b/arch/arm/mach-imx/pm-imx6.c @@ -89,7 +89,6 @@ struct imx6_pm_base { struct imx6_pm_socdata { u32 ddr_type; - const char *ccm_compat; const char *mmdc_compat; const char *src_compat; const char *iomuxc_compat; @@ -139,7 +138,6 @@ static const u32 imx6sx_mmdc_io_offset[] __initconst = { }; static const struct imx6_pm_socdata imx6q_pm_data __initconst = { - .ccm_compat = "fsl,imx6q-ccm", .mmdc_compat = "fsl,imx6q-mmdc", .src_compat = "fsl,imx6q-src", .iomuxc_compat = "fsl,imx6q-iomuxc", @@ -149,7 +147,6 @@ static const struct imx6_pm_socdata imx6q_pm_data __initconst = { }; static const struct imx6_pm_socdata imx6dl_pm_data __initconst = { - .ccm_compat = "fsl,imx6q-ccm", .mmdc_compat = "fsl,imx6q-mmdc", .src_compat = "fsl,imx6q-src", .iomuxc_compat = "fsl,imx6dl-iomuxc", @@ -159,7 +156,6 @@ static const struct imx6_pm_socdata imx6dl_pm_data __initconst = { }; static const struct imx6_pm_socdata imx6sl_pm_data __initconst = { - .ccm_compat = "fsl,imx6sl-ccm", .mmdc_compat = "fsl,imx6sl-mmdc", .src_compat = "fsl,imx6sl-src", .iomuxc_compat = "fsl,imx6sl-iomuxc", @@ -169,7 +165,6 @@ static const struct imx6_pm_socdata imx6sl_pm_data __initconst = { }; static const struct imx6_pm_socdata imx6sx_pm_data __initconst = { - .ccm_compat = "fsl,imx6sx-ccm", .mmdc_compat = "fsl,imx6sx-mmdc", .src_compat = "fsl,imx6sx-src", .iomuxc_compat = "fsl,imx6sx-iomuxc", @@ -553,16 +548,11 @@ put_node: static void __init imx6_pm_common_init(const struct imx6_pm_socdata *socdata) { - struct device_node *np; struct regmap *gpr; int ret; - np = of_find_compatible_node(NULL, NULL, socdata->ccm_compat); - ccm_base = of_iomap(np, 0); WARN_ON(!ccm_base); - imx6_set_lpm(WAIT_CLOCKED); - if (IS_ENABLED(CONFIG_SUSPEND)) { ret = imx6q_suspend_init(socdata); if (ret) @@ -583,6 +573,24 @@ static void __init imx6_pm_common_init(const struct imx6_pm_socdata IMX6Q_GPR1_GINT); } +void __init imx6_pm_ccm_init(const char *ccm_compat) +{ + struct device_node *np; + u32 val; + + np = of_find_compatible_node(NULL, NULL, ccm_compat); + ccm_base = of_iomap(np, 0); + BUG_ON(!ccm_base); + + /* + * Initialize CCM_CLPCR_LPM into RUN mode to avoid ARM core + * clock being shut down unexpectedly by WAIT mode. + */ + val = readl_relaxed(ccm_base + CLPCR); + val &= ~BM_CLPCR_LPM; + writel_relaxed(val, ccm_base + CLPCR); +} + void __init imx6q_pm_init(void) { imx6_pm_common_init(&imx6q_pm_data);