From patchwork Mon Jan 14 18:16:40 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephen Warren X-Patchwork-Id: 211855 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id C23462C0094 for ; Tue, 15 Jan 2013 05:16:49 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757353Ab3ANSQs (ORCPT ); Mon, 14 Jan 2013 13:16:48 -0500 Received: from avon.wwwdotorg.org ([70.85.31.133]:46820 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756462Ab3ANSQs (ORCPT ); Mon, 14 Jan 2013 13:16:48 -0500 Received: from severn.wwwdotorg.org (unknown [192.168.65.5]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by avon.wwwdotorg.org (Postfix) with ESMTPS id 19E396305; Mon, 14 Jan 2013 11:18:18 -0700 (MST) Received: from swarren-lx1.nvidia.com (localhost [127.0.0.1]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by severn.wwwdotorg.org (Postfix) with ESMTPSA id A7434E479F; Mon, 14 Jan 2013 11:16:45 -0700 (MST) From: Stephen Warren To: mturquette@linaro.org Cc: Prashant Gaikwad , Laxman Dewangan , linux-tegra@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Stephen Warren Subject: [PATCH] clk: tegra: ensure all provided clock values are valid cookies Date: Mon, 14 Jan 2013 11:16:40 -0700 Message-Id: <1358187400-6824-1-git-send-email-swarren@wwwdotorg.org> X-Mailer: git-send-email 1.7.10.4 X-NVConfidentiality: public X-Virus-Scanned: clamav-milter 0.96.5 at avon.wwwdotorg.org X-Virus-Status: Clean Sender: linux-tegra-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org From: Stephen Warren Tegra's clock implementation uses pointers as the clock cookies, and hence chooses to make NULL an invalid clock cookie. However, there are gaps in the assigned device tree clock IDs, and hence the array mapping DT clock ID contains entries with NULL values (uninitialized BSS) unless explicit action is taken. This patch enhances the Tegra clock code to detect this case and explicitly initialize those lookup table entries to an error value. This prevents clk_get() from ever returning NULL. Hence, Tegra's clock APIs don't have to check the clock cookie they're passed for NULL. Signed-off-by: Stephen Warren --- Mike, this also will need to go through the Tegra tree; just looking for any review/ack from you. Thanks. drivers/clk/tegra/clk-tegra20.c | 5 ++++- drivers/clk/tegra/clk-tegra30.c | 5 ++++- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/clk/tegra/clk-tegra20.c b/drivers/clk/tegra/clk-tegra20.c index 5847b5e..e59ac14 100644 --- a/drivers/clk/tegra/clk-tegra20.c +++ b/drivers/clk/tegra/clk-tegra20.c @@ -1243,12 +1243,15 @@ void __init tegra20_clock_init(struct device_node *np) tegra20_audio_clk_init(); - for (i = 0; i < ARRAY_SIZE(clks); i++) + for (i = 0; i < ARRAY_SIZE(clks); i++) { if (IS_ERR(clks[i])) { pr_err("Tegra20 clk %d: register failed with %ld\n", i, PTR_ERR(clks[i])); BUG(); } + if (!clks[i]) + clks[i] = ERR_PTR(-EINVAL); + } tegra_init_dup_clks(tegra_clk_duplicates, clks, clk_max); diff --git a/drivers/clk/tegra/clk-tegra30.c b/drivers/clk/tegra/clk-tegra30.c index 987312c..9c0b2ee 100644 --- a/drivers/clk/tegra/clk-tegra30.c +++ b/drivers/clk/tegra/clk-tegra30.c @@ -2022,12 +2022,15 @@ void __init tegra30_clock_init(struct device_node *np) tegra30_audio_clk_init(); tegra30_pmc_clk_init(); - for (i = 0; i < ARRAY_SIZE(clks); i++) + for (i = 0; i < ARRAY_SIZE(clks); i++) { if (IS_ERR(clks[i])) { pr_err("Tegra30 clk %d: register failed with %ld\n", i, PTR_ERR(clks[i])); BUG(); } + if (!clks[i]) + clks[i] = ERR_PTR(-EINVAL); + } tegra_init_dup_clks(tegra_clk_duplicates, clks, clk_max);