From patchwork Thu Jun 16 15:15:28 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sudeep Holla X-Patchwork-Id: 70193 Delivered-To: patch@linaro.org Received: by 10.140.28.4 with SMTP id 4csp316159qgy; Thu, 16 Jun 2016 08:17:15 -0700 (PDT) X-Received: by 10.98.21.4 with SMTP id 4mr5732489pfv.92.1466090235349; Thu, 16 Jun 2016 08:17:15 -0700 (PDT) Return-Path: Received: from bombadil.infradead.org (bombadil.infradead.org. [2001:1868:205::9]) by mx.google.com with ESMTPS id z62si6428208pfb.179.2016.06.16.08.17.15 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 16 Jun 2016 08:17:15 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org designates 2001:1868:205::9 as permitted sender) client-ip=2001:1868:205::9; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org designates 2001:1868:205::9 as permitted sender) smtp.mailfrom=linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org 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 1bDZ1T-0007VZ-M6; Thu, 16 Jun 2016 15:15:59 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1bDZ1R-0007AM-60 for linux-arm-kernel@lists.infradead.org; Thu, 16 Jun 2016 15:15:57 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2DBD5F; Thu, 16 Jun 2016 08:16:18 -0700 (PDT) Received: from e107155-lin.cambridge.arm.com (e107155-lin.cambridge.arm.com [10.1.207.44]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B3DF43F246; Thu, 16 Jun 2016 08:15:34 -0700 (PDT) From: Sudeep Holla To: linux-arm-kernel@lists.infradead.org, arm@kernel.org Subject: [PATCH] arm64: Kconfig: select PM for ARCH_VEXPRESS Date: Thu, 16 Jun 2016 16:15:28 +0100 Message-Id: <1466090128-24425-1-git-send-email-sudeep.holla@arm.com> X-Mailer: git-send-email 2.7.4 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160616_081557_313011_1EF8A925 X-CRM114-Status: GOOD ( 10.87 ) X-Spam-Score: -8.3 (--------) X-Spam-Report: SpamAssassin version 3.4.0 on bombadil.infradead.org summary: Content analysis details: (-8.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/, high trust [217.140.101.70 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -1.4 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Ulf Hansson , Arnd Bergmann , Kevin Hilman , Catalin Marinas , Will Deacon , Sudeep Holla , Olof Johansson MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org The Linux AMBA bus framework probes the peripheral IDs when adding the AMBA devices very early on the boot. Generally they are on APB bus and just require APB clocks to be on even when most of the core logic of the IP is powered down. However on Juno, the entire debugsys domain needs to be ON to access even the coresight components' CID/PID registers and hence broken by design. Accessing those while debugsys power domain is off will lead to the bridge stalling the transactions instead of returning the slave error. Further, the AMBA framework can't deal with !CONFIG_PM case: it ignores the error and proceeds to access the device region. It was suggested to always enable CONFIG_PM in order to handle this scenario. Suggested-by: Ulf Hansson Signed-off-by: Sudeep Holla --- arch/arm64/Kconfig.platforms | 1 + 1 file changed, 1 insertion(+) Hi ARM-SoC team, The discussion on this happened on linux-pm list[1]. This is need on Juno once we introduce coresight components in the DT. With !CONFIG_PM, the board stalls on boot and hence this patch is needed. This shouldn't change any thing in the defconfig as couple of other platforms already do the same. It's needed in case all other ARCH_* configs are disabled. Without this, we need a dirty trick in the DT[2] to handle !CONFIG_PM. Can you please pick this for v4.8 ? Regards, Sudeep [1] http://marc.info/?l=linux-pm&m=146607608629880&w=2 [2] https://marc.info/?l=linux-arm-kernel&m=146522896503670&w=2 -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms index 7ef1d05859ae..8983ab14c9ca 100644 --- a/arch/arm64/Kconfig.platforms +++ b/arch/arm64/Kconfig.platforms @@ -160,6 +160,7 @@ config ARCH_VEXPRESS bool "ARMv8 software model (Versatile Express)" select ARCH_REQUIRE_GPIOLIB select COMMON_CLK_VERSATILE + select PM select POWER_RESET_VEXPRESS select VEXPRESS_CONFIG help