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=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 11D25C83026 for ; Thu, 3 Dec 2020 13:39:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6C5BC20637 for ; Thu, 3 Dec 2020 13:39:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437099AbgLCNh7 (ORCPT ); Thu, 3 Dec 2020 08:37:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:47986 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2436464AbgLCNaD (ORCPT ); Thu, 3 Dec 2020 08:30:03 -0500 From: Sasha Levin Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Can Guo , Stanley Chu , "Martin K . Petersen" , Sasha Levin , linux-scsi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: [PATCH AUTOSEL 5.9 13/39] scsi: ufs: Make sure clk scaling happens only when HBA is runtime ACTIVE Date: Thu, 3 Dec 2020 08:28:07 -0500 Message-Id: <20201203132834.930999-13-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20201203132834.930999-1-sashal@kernel.org> References: <20201203132834.930999-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 cbcdd79a1f76f..18326eb772aeb 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -1279,8 +1279,15 @@ 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