From patchwork Tue Jun 30 12:48:24 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lucas Stach X-Patchwork-Id: 6695941 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 F263F9F40A for ; Tue, 30 Jun 2015 12:51:11 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 163F920425 for ; Tue, 30 Jun 2015 12:51:11 +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 E68FD203F7 for ; Tue, 30 Jun 2015 12:51:09 +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 1Z9uy6-0006bR-PO; Tue, 30 Jun 2015 12:48:54 +0000 Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Z9uy3-0006UE-8Z for linux-arm-kernel@lists.infradead.org; Tue, 30 Jun 2015 12:48:52 +0000 Received: from dude.hi.4.pengutronix.de ([10.1.0.7] helo=dude.pengutronix.de.) by metis.ext.pengutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1Z9t5f-0002vs-L4; Tue, 30 Jun 2015 12:48:35 +0200 From: Lucas Stach To: Shawn Guo Subject: [PATCH] ARM: imx6: gpc: always enable PU domain if CONFIG_PM is not set Date: Tue, 30 Jun 2015 14:48:24 +0200 Message-Id: <1435668504-26945-1-git-send-email-l.stach@pengutronix.de> X-Mailer: git-send-email 2.1.4 X-SA-Exim-Connect-IP: 10.1.0.7 X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-arm-kernel@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150630_054851_643220_6B5B7B40 X-CRM114-Status: GOOD ( 17.21 ) X-Spam-Score: -2.5 (--) Cc: kernel@pengutronix.de, linux-arm-kernel@lists.infradead.org, patchwork-lst@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=-4.8 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, 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 If CONFIG_PM is not set the PU power domain needs to be enabled always, otherwise there are two failure scenarios which will hang the system if one of the devices in the PU domain is accessed. 1. New DTs (4.1+) drop the "always-on" property from the PU regulator, so if it isn't properly enabled by the GPC code it will be disabled at the end of boot. 2. If the bootloader already disabled the PU domain the GPC explicitly needs to enable it again, even if the kernel doesn't do any power management. This is a bit hypothetical, as it requires to boot a mainline kernel on a downstream bootloader, as no mainline bootloader disables the PM domains. Cc: # 4.1 Signed-off-by: Lucas Stach Acked-by: Philipp Zabel --- arch/arm/mach-imx/gpc.c | 27 ++++++--------------------- 1 file changed, 6 insertions(+), 21 deletions(-) diff --git a/arch/arm/mach-imx/gpc.c b/arch/arm/mach-imx/gpc.c index 6d0893a3828e..78b6fd0b86e6 100644 --- a/arch/arm/mach-imx/gpc.c +++ b/arch/arm/mach-imx/gpc.c @@ -291,8 +291,6 @@ void __init imx_gpc_check_dt(void) } } -#ifdef CONFIG_PM_GENERIC_DOMAINS - static void _imx6q_pm_pu_power_off(struct generic_pm_domain *genpd) { int iso, iso2sw; @@ -399,7 +397,6 @@ static struct genpd_onecell_data imx_gpc_onecell_data = { static int imx_gpc_genpd_init(struct device *dev, struct regulator *pu_reg) { struct clk *clk; - bool is_off; int i; imx6q_pu_domain.reg = pu_reg; @@ -416,18 +413,13 @@ static int imx_gpc_genpd_init(struct device *dev, struct regulator *pu_reg) } imx6q_pu_domain.num_clks = i; - is_off = IS_ENABLED(CONFIG_PM); - if (is_off) { - _imx6q_pm_pu_power_off(&imx6q_pu_domain.base); - } else { - /* - * Enable power if compiled without CONFIG_PM in case the - * bootloader disabled it. - */ - imx6q_pm_pu_power_on(&imx6q_pu_domain.base); - } + /* Enable power always in case bootloader disabled it. */ + imx6q_pm_pu_power_on(&imx6q_pu_domain.base); + + if (!IS_ENABLED(CONFIG_PM_GENERIC_DOMAINS)) + return 0; - pm_genpd_init(&imx6q_pu_domain.base, NULL, is_off); + pm_genpd_init(&imx6q_pu_domain.base, NULL, false); return of_genpd_add_provider_onecell(dev->of_node, &imx_gpc_onecell_data); @@ -437,13 +429,6 @@ clk_err: return -EINVAL; } -#else -static inline int imx_gpc_genpd_init(struct device *dev, struct regulator *reg) -{ - return 0; -} -#endif /* CONFIG_PM_GENERIC_DOMAINS */ - static int imx_gpc_probe(struct platform_device *pdev) { struct regulator *pu_reg;