From patchwork Tue May 26 16:43:36 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lucas Stach X-Patchwork-Id: 6484231 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id AD927C0020 for ; Tue, 26 May 2015 16:50:28 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7D76420650 for ; Tue, 26 May 2015 16:50:26 +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 6F31120653 for ; Tue, 26 May 2015 16:50:25 +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 1YxI0S-0006mB-45; Tue, 26 May 2015 16:47:08 +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 1YxHxR-00032c-Pl for linux-arm-kernel@lists.infradead.org; Tue, 26 May 2015 16:44:02 +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 1YxHx3-0004uW-JJ; Tue, 26 May 2015 18:43:37 +0200 From: Lucas Stach To: Shawn Guo Subject: [PATCH] ARM: imx6: allow booting with old DT Date: Tue, 26 May 2015 18:43:36 +0200 Message-Id: <1432658616-13733-1-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-20150526_094402_073295_862B3210 X-CRM114-Status: GOOD ( 16.52 ) X-Spam-Score: -0.0 (/) Cc: Marc Zyngier , kernel@pengutronix.de, linux-arm-kernel@lists.infradead.org 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 The GPC rewrite to IRQ domains has been on the premise that it may break suspend/resume for new kernels on old DT, but otherwise keep things working from a user perspective. This was an accepted compromise to be able to move the GIC cleanup forward. What actually happened was that booting a new kernel on an old DT crashes before even the console is up, so the user does not even see the warning that the DT is too old. The warning message suggests that this has been known before, which is clearly unacceptable. Fix the early crash by mapping the GPC memory space if the IRQ controller doesn't claim it. This keeps at least CPUidle and the needed CPU wakeup workarounds working. With this fixed the system is able to boot up properly minus the expected suspend/resume breakage. Signed-off-by: Lucas Stach --- Shawn, this is a critical fix for 4.1, to keep the combination of old DT + new kernel at least somewhat working, to allow users to resolve the situation on their systems. Please make sure this gets forwarded ASAP. --- arch/arm/mach-imx/gpc.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/arm/mach-imx/gpc.c b/arch/arm/mach-imx/gpc.c index 4d60005e9277..bbf015056221 100644 --- a/arch/arm/mach-imx/gpc.c +++ b/arch/arm/mach-imx/gpc.c @@ -280,9 +280,15 @@ void __init imx_gpc_check_dt(void) struct device_node *np; np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-gpc"); - if (WARN_ON(!np || - !of_find_property(np, "interrupt-controller", NULL))) - pr_warn("Outdated DT detected, system is about to crash!!!\n"); + if (WARN_ON(!np)) + return; + + if (WARN_ON(!of_find_property(np, "interrupt-controller", NULL))) { + pr_warn("Outdated DT detected, suspend/resume will NOT work\n"); + + /* map GPC, so that at least CPUidle and WARs keep working */ + gpc_base = of_iomap(np, 0); + } } #ifdef CONFIG_PM_GENERIC_DOMAINS