From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3F7A7C3527B for ; Mon, 21 Feb 2022 10:03:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354001AbiBUKCn (ORCPT ); Mon, 21 Feb 2022 05:02:43 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:34484 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352139AbiBUJzF (ORCPT ); Mon, 21 Feb 2022 04:55:05 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5C208381A3; Mon, 21 Feb 2022 01:24:06 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 0A7EEB80ED2; Mon, 21 Feb 2022 09:24:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 18AEFC340E9; Mon, 21 Feb 2022 09:24:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1645435443; bh=/NW4lK+cwpAZ+jx+0oSMQYbrYONrpg8H23rLb64Kxbk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0IvtL5SZs9QbnRqWhy4eOqA20hvI/pEdMXFwKir2ESJIN6C1/80PzTuO/cm/4QlfK ZjDQJh4UDpdo3+RuCYKuyHUFJNSWKJFjKjBf3adBsl2PVqzKwDOSl5UH7vHeHwiyRr ynjPNOotqgQIHkG0Smkgny+wnZhCi2sIFZV/GMgE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bryan ODonoghue , Manivannan Sadhasivam , Miquel Raynal Subject: [PATCH 5.16 165/227] mtd: rawnand: qcom: Fix clock sequencing in qcom_nandc_probe() Date: Mon, 21 Feb 2022 09:49:44 +0100 Message-Id: <20220221084940.312532056@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220221084934.836145070@linuxfoundation.org> References: <20220221084934.836145070@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Bryan O'Donoghue commit 5c23b3f965bc9ee696bf2ed4bdc54d339dd9a455 upstream. Interacting with a NAND chip on an IPQ6018 I found that the qcomsmem NAND partition parser was returning -EPROBE_DEFER waiting for the main smem driver to load. This caused the board to reset. Playing about with the probe() function shows that the problem lies in the core clock being switched off before the nandc_unalloc() routine has completed. If we look at how qcom_nandc_remove() tears down allocated resources we see the expected order is qcom_nandc_unalloc(nandc); clk_disable_unprepare(nandc->aon_clk); clk_disable_unprepare(nandc->core_clk); dma_unmap_resource(&pdev->dev, nandc->base_dma, resource_size(res), DMA_BIDIRECTIONAL, 0); Tweaking probe() to both bring up and tear-down in that order removes the reset if we end up deferring elsewhere. Fixes: c76b78d8ec05 ("mtd: nand: Qualcomm NAND controller driver") Signed-off-by: Bryan O'Donoghue Reviewed-by: Manivannan Sadhasivam Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20220103030316.58301-2-bryan.odonoghue@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/mtd/nand/raw/qcom_nandc.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) --- a/drivers/mtd/nand/raw/qcom_nandc.c +++ b/drivers/mtd/nand/raw/qcom_nandc.c @@ -2,7 +2,6 @@ /* * Copyright (c) 2016, The Linux Foundation. All rights reserved. */ - #include #include #include @@ -3063,10 +3062,6 @@ static int qcom_nandc_probe(struct platf if (dma_mapping_error(dev, nandc->base_dma)) return -ENXIO; - ret = qcom_nandc_alloc(nandc); - if (ret) - goto err_nandc_alloc; - ret = clk_prepare_enable(nandc->core_clk); if (ret) goto err_core_clk; @@ -3075,6 +3070,10 @@ static int qcom_nandc_probe(struct platf if (ret) goto err_aon_clk; + ret = qcom_nandc_alloc(nandc); + if (ret) + goto err_nandc_alloc; + ret = qcom_nandc_setup(nandc); if (ret) goto err_setup; @@ -3086,15 +3085,14 @@ static int qcom_nandc_probe(struct platf return 0; err_setup: + qcom_nandc_unalloc(nandc); +err_nandc_alloc: clk_disable_unprepare(nandc->aon_clk); err_aon_clk: clk_disable_unprepare(nandc->core_clk); err_core_clk: - qcom_nandc_unalloc(nandc); -err_nandc_alloc: dma_unmap_resource(dev, res->start, resource_size(res), DMA_BIDIRECTIONAL, 0); - return ret; }