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: 2673881 Return-Path: X-Original-To: patchwork-linux-samsung-soc@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id F026540077 for ; Wed, 5 Jun 2013 20:57:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932202Ab3FEU5D (ORCPT ); Wed, 5 Jun 2013 16:57:03 -0400 Received: from mail-qc0-f202.google.com ([209.85.216.202]:52976 "EHLO mail-qc0-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932319Ab3FEU5A (ORCPT ); Wed, 5 Jun 2013 16:57:00 -0400 Received: by mail-qc0-f202.google.com with SMTP id d1so197494qcz.5 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=iuwoCmf0xDl4HkFIMgbqHp41imbkDKprrNilv5KOxBxCRfMoL7SxGfQ29BoON+K4zb eUrLcCt6DQUiHG6MdsqfwjOqbinTo58CxxOcCR3PzwZoGy5uN8wxDXnPPO2FJLfOGB/B aWhTcx4UvRdVk9EMDb+iD0eNzImD8bdQNqyNNekFTajfChgZ9KCTsH+KPl5dQxEqQTFL HQfhCcJt6KZbtNTPLN555Y2nxF33mi/nf1zsnQSk0Me6gAKQQWHcfsZ0GbcTooOdXhQF XdQZWun4iVNFoaUVqkY57i7v9VgEKeHr5iivyujIazUdKcLhFmxvjtrYeMX6FDUhcK8N 29SA== 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 Cc: Thomas Abraham , Simon Glass , linux-samsung-soc@vger.kernel.org, Tomasz Figa , Russell King , Ben Dooks , Doug Anderson , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org 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: ALoCoQntTGAVM1uC+w/kCJkKSEPIOIyaFeu06oxpnnu7xtQcyuJTx2yCZFH9e9kwksUBtqnuMOBwSP+lSSZhtPphBAfoOWpb8F6oXqIDHPRUi2B8+jao5YCFj4cDfzGrLuZ22ETQQktmTshRblyxNP2ALxpUHLLCmiTaAEQyXx9FWKZamolM0rb0XQMqC5YFm7gi5TfPvHhUHCxIp19CJr2gxfYh2Y9kLQ== Sender: linux-samsung-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.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);