From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752295AbcI1JRu (ORCPT ); Wed, 28 Sep 2016 05:17:50 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57808 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752921AbcI1JMD (ORCPT ); Wed, 28 Sep 2016 05:12:03 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jon Hunter , Thierry Reding Subject: [PATCH 4.7 63/69] soc/tegra: pmc: Dont probe PMC if early initialisation fails Date: Wed, 28 Sep 2016 11:05:45 +0200 Message-Id: <20160928090447.721810961@linuxfoundation.org> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20160928090445.054716307@linuxfoundation.org> References: <20160928090445.054716307@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jon Hunter commit a83f1fc3f33930d01e579b9d4de92a045297b402 upstream. Commit 0259f522e04f ('soc/tegra: pmc: Restore base address on probe failure') fixes an issue where the PMC base address pointer is not restored on probe failure. However, this fix creates another problem where if early initialisation of the PMC driver fails and an initial mapping for the PMC address space is not created, then when the PMC device is probed, the PMC base address pointer will not be valid and this will cause a crash when tegra_pmc_init() is called and attempts to access a register. Although the PMC address space is mapped a 2nd time during the probe and so this could be fixed by populating the base address pointer earlier during the probe, this adds more complexity to the code. Moreover, the PMC probe also assumes the the soc data pointer is also initialised when the device is probed and if not will also lead to a crash when calling tegra_pmc_init_tsense_reset(). Given that if the early initialisation does fail then something bad has happen, it seems acceptable to allow the PMC device probe to fail as well. Therefore, if the PMC base address pointer or soc data pointer are not valid when probing the PMC device, WARN and return an error. Fixes: 0259f522e04f ('soc/tegra: pmc: Restore base address on probe failure') Signed-off-by: Jon Hunter Signed-off-by: Thierry Reding Signed-off-by: Greg Kroah-Hartman --- drivers/soc/tegra/pmc.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/drivers/soc/tegra/pmc.c +++ b/drivers/soc/tegra/pmc.c @@ -1205,6 +1205,14 @@ static int tegra_pmc_probe(struct platfo struct resource *res; int err; + /* + * Early initialisation should have configured an initial + * register mapping and setup the soc data pointer. If these + * are not valid then something went badly wrong! + */ + if (WARN_ON(!pmc->base || !pmc->soc)) + return -ENODEV; + err = tegra_pmc_parse_dt(pmc, pdev->dev.of_node); if (err < 0) return err;