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 X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,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 91E33C4332E for ; Mon, 28 Dec 2020 16:14:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7101820829 for ; Mon, 28 Dec 2020 16:14:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2633025AbgL1QOD (ORCPT ); Mon, 28 Dec 2020 11:14:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:47540 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732888AbgL1NTa (ORCPT ); Mon, 28 Dec 2020 08:19:30 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 954B5229EF; Mon, 28 Dec 2020 13:19:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609161555; bh=ci1MjAVcgwcF2qCORpOQ/On47tm2ofvYsfTkVdFquWU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xaNNyVl9uoHzH23BrXxRYodBflR9OZRWRYUvUQIFTTKFx1VD7tKiKEhp17uacxqvH ES78xYNfeIoD1MucFn7+rit8Zy0odOEeIjZKvJZ+rRFKP6VJrAWcskqcVi2jQehkWN lI1e2ZzuFvNHwYZwwNzJCILnloXhpCRXimX9FvpQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stanley Chu , Can Guo , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 4.19 010/346] scsi: ufs: Make sure clk scaling happens only when HBA is runtime ACTIVE Date: Mon, 28 Dec 2020 13:45:29 +0100 Message-Id: <20201228124920.260848214@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228124919.745526410@linuxfoundation.org> References: <20201228124919.745526410@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: Can Guo [ Upstream commit 73cc291c270248567245f084dcdf5078069af6b5 ] If someone plays with the UFS clk scaling devfreq governor through sysfs, ufshcd_devfreq_scale may be called even when HBA is not runtime ACTIVE. This can lead to unexpected error. We cannot just protect it by calling pm_runtime_get_sync() because that may cause a race condition since HBA runtime suspend ops need to suspend clk scaling. To fix this call pm_runtime_get_noresume() and check HBA's runtime status. Only proceed if HBA is runtime ACTIVE, otherwise just bail. governor_store devfreq_performance_handler update_devfreq devfreq_set_target ufshcd_devfreq_target ufshcd_devfreq_scale Link: https://lore.kernel.org/r/1600758548-28576-1-git-send-email-cang@codeaurora.org Reviewed-by: Stanley Chu Signed-off-by: Can Guo Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/ufs/ufshcd.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 7e4e6e982055e..61b1eae42ea85 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -1281,8 +1281,15 @@ static int ufshcd_devfreq_target(struct device *dev, } spin_unlock_irqrestore(hba->host->host_lock, irq_flags); + pm_runtime_get_noresume(hba->dev); + if (!pm_runtime_active(hba->dev)) { + pm_runtime_put_noidle(hba->dev); + ret = -EAGAIN; + goto out; + } start = ktime_get(); ret = ufshcd_devfreq_scale(hba, scale_up); + pm_runtime_put(hba->dev); trace_ufshcd_profile_clk_scaling(dev_name(hba->dev), (scale_up ? "up" : "down"), -- 2.27.0