From patchwork Wed Jun 5 20:56:33 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 2673891 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) by patchwork1.kernel.org (Postfix) with ESMTP id 5A0CD40077 for ; Wed, 5 Jun 2013 20:57:56 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UkKlz-0001En-Ec; Wed, 05 Jun 2013 20:57:35 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UkKls-0006j9-To; Wed, 05 Jun 2013 20:57:28 +0000 Received: from mail-qc0-x24a.google.com ([2607:f8b0:400d:c01::24a]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UkKll-0006ho-2I for linux-arm-kernel@lists.infradead.org; Wed, 05 Jun 2013 20:57:22 +0000 Received: by mail-qc0-f202.google.com with SMTP id d1so197592qcz.3 for ; Wed, 05 Jun 2013 13:56:59 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references :x-gm-message-state; bh=s+C2QxbWU/tKACn1onGNPqPQX6SBFdPlNkRMRHn28ZE=; b=eHaCWcJa9Lbo/ziGPk8ATkCdbnhUXpjiI0q97eGjqR8MBalR8ITvRm9wy6ov5f1ySf zFHWYNqZMDOTjJYtZxVPs2vsAYy8U6Edap9srco+YxukrEaXa/NnGBX7gAsPUDv4Zwz3 RDLqvHIIU7Uc0dgUwymsTQdizcui+OueQQrgSh53pFGfDucZOI74T8jP0I6w3t2KPyS0 v1Z1RuI6Tu1jvgVQAb1RlqxbTFp6x2FOdLH/wGm5Z/6FF54oFsV3sdLShYVGlkDOLUGh rT/V+sGvzBKVoNafnbNeCwuhX8ITKw8+Wo1/QdGCQqQKu9fugooewtiQkjbl6bI0poJk /BuQ== X-Received: by 10.236.21.198 with SMTP id r46mr17483589yhr.12.1370465819889; Wed, 05 Jun 2013 13:56:59 -0700 (PDT) Received: from corp2gmr1-2.hot.corp.google.com (corp2gmr1-2.hot.corp.google.com [172.24.189.93]) by gmr-mx.google.com with ESMTPS id g80si194923yhj.7.2013.06.05.13.56.59 for (version=TLSv1.1 cipher=AES128-SHA bits=128/128); Wed, 05 Jun 2013 13:56:59 -0700 (PDT) Received: from tictac.mtv.corp.google.com (tictac.mtv.corp.google.com [172.22.162.34]) by corp2gmr1-2.hot.corp.google.com (Postfix) with ESMTP id B05515A41FA; Wed, 5 Jun 2013 13:56:59 -0700 (PDT) Received: by tictac.mtv.corp.google.com (Postfix, from userid 121310) id 441FA80DB1; Wed, 5 Jun 2013 13:56:59 -0700 (PDT) From: Doug Anderson To: Kukjin Kim , Olof Johansson Subject: [PATCH v2] ARM: exynos: add debug_ll_io_init() call in exynos_init_io() Date: Wed, 5 Jun 2013 13:56:33 -0700 Message-Id: <1370465793-7997-1-git-send-email-dianders@chromium.org> X-Mailer: git-send-email 1.8.3 In-Reply-To: <1370397539-21653-1-git-send-email-dianders@chromium.org> References: <1370397539-21653-1-git-send-email-dianders@chromium.org> X-Gm-Message-State: ALoCoQk69pRh/8asUM3UF7/9KInOIR3fKnzwU5HT0auUqlR+N789+bQ15ifThdo53EbvBSqsiNtaoFPdMJCxy1yMIkZpvvlPTrE6FOEPfF8wFfCLlt336M+h7IkwO0yltbTe1u7K70ZM4FSrWBU67+o8rT4dN7c3CMJlKNOGSqWtRjp0bLK+UfyuVGFHOZCT9iezfGi4jl5Pbi9sZINdQnyAhup2rzqjkw== X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130605_165721_236176_1925A332 X-CRM114-Status: GOOD ( 12.24 ) X-Spam-Score: -2.4 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.4 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record -0.5 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] Cc: linux-samsung-soc@vger.kernel.org, Russell King , linux-kernel@vger.kernel.org, Simon Glass , Tomasz Figa , Doug Anderson , Thomas Abraham , Ben Dooks , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 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 If the early MMU mapping of the UART happens to get booted out of the TLB between the start of paging_init() and when we finally re-add the UART at the very end of s3c_init_cpu(), we'll get a hang at bootup if we've got early_printk enabled. Avoid this hang by calling debug_ll_io_init() early. Without this patch, you can reliably reproduce a hang when early printk is enabled by adding flush_tlb_all() at the start of exynos_init_io(). After this patch the hang goes away. Signed-off-by: Doug Anderson Acked-by: Olof Johansson Acked-by: Kukjin Kim --- Changes in v2: - Use debug_ll_io_init() instead of reordering printks and adding warnings. Thanks Olof! arch/arm/mach-exynos/common.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/mach-exynos/common.c b/arch/arm/mach-exynos/common.c index 027c9e7..f7e504b 100644 --- a/arch/arm/mach-exynos/common.c +++ b/arch/arm/mach-exynos/common.c @@ -386,6 +386,8 @@ int __init exynos_fdt_map_chipid(unsigned long node, const char *uname, void __init exynos_init_io(struct map_desc *mach_desc, int size) { + debug_ll_io_init(); + #ifdef CONFIG_OF if (initial_boot_params) of_scan_flat_dt(exynos_fdt_map_chipid, NULL);