From patchwork Mon Mar 1 16:10:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 389792 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 585F4C433E0 for ; Mon, 1 Mar 2021 18:07:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 238D765213 for ; Mon, 1 Mar 2021 18:07:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239168AbhCASHU (ORCPT ); Mon, 1 Mar 2021 13:07:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:52458 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238325AbhCASBa (ORCPT ); Mon, 1 Mar 2021 13:01:30 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6BF34651AC; Mon, 1 Mar 2021 17:21:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614619288; bh=rK3a5NaRhJhvHTt3kevhobOks/qIUC/K0EwM4prBEYw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SeJDX+ao1o1CrlnVExUBc+u7ARxr5r7kCqs5JNYjzf176elZ9lbsdsfoQwVCMRU/W ykQFcXsJ5bq6X5xCRDL3AQft2JIU0FWu2W0BjWXad3/o1/CtAlilJTm/sdIHqAZu3M XPCq678BfKL17mv5HLqJbV0b1OByCeUbs7Pw7fVI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thierry Reding , Trent Piepho , Simon South , Sasha Levin Subject: [PATCH 5.10 401/663] pwm: rockchip: Enable APB clock during register access while probing Date: Mon, 1 Mar 2021 17:10:49 +0100 Message-Id: <20210301161201.711100535@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161141.760350206@linuxfoundation.org> References: <20210301161141.760350206@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Simon South [ Upstream commit d9b657a5cdbd960de35dee7e06473caf44a9016f ] Commit 457f74abbed0 ("pwm: rockchip: Keep enabled PWMs running while probing") modified rockchip_pwm_probe() to access a PWM device's registers directly to check whether or not the device is enabled, but did not also change the function so it first enables the device's APB clock to be certain the device can respond. This risks hanging the kernel on systems with PWM devices that use more than a single clock. Avoid this by enabling the device's APB clock before accessing its registers (and disabling the clock when register access is complete). Fixes: 457f74abbed0 ("pwm: rockchip: Keep enabled PWMs running while probing") Reported-by: Thierry Reding Suggested-by: Trent Piepho Signed-off-by: Simon South Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin --- drivers/pwm/pwm-rockchip.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c index 77c23a2c6d71e..7b9cdefb3daa3 100644 --- a/drivers/pwm/pwm-rockchip.c +++ b/drivers/pwm/pwm-rockchip.c @@ -332,9 +332,9 @@ static int rockchip_pwm_probe(struct platform_device *pdev) return ret; } - ret = clk_prepare(pc->pclk); + ret = clk_prepare_enable(pc->pclk); if (ret) { - dev_err(&pdev->dev, "Can't prepare APB clk: %d\n", ret); + dev_err(&pdev->dev, "Can't prepare enable APB clk: %d\n", ret); goto err_clk; } @@ -364,10 +364,12 @@ static int rockchip_pwm_probe(struct platform_device *pdev) if ((ctrl & enable_conf) != enable_conf) clk_disable(pc->clk); + clk_disable(pc->pclk); + return 0; err_pclk: - clk_unprepare(pc->pclk); + clk_disable_unprepare(pc->pclk); err_clk: clk_disable_unprepare(pc->clk);