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=-14.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 2DEA6C433E1 for ; Mon, 24 Aug 2020 16:56:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0A030204EA for ; Mon, 24 Aug 2020 16:56:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598288210; bh=TFQLrnd/E0M/aKPZvow4lTZFI5KdHTF5ZWkw7zGVU2w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wX27QIerZ3JYaTQ3UGc5+QcJbO+XJnokY9zdMCiYesBGEeCdjQ3GVYrQZU+w6B23k yNdUP/n0r06p8OMAI4/UmuaM5axpREo2bX6Q/lOiAuk4biWLByqIYydsQoMif4iEWN uMV7MZdnCKnlyjf6WFt/axzUG6+0ZlOuBulItPkY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726531AbgHXQ4s (ORCPT ); Mon, 24 Aug 2020 12:56:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:40360 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728543AbgHXQjD (ORCPT ); Mon, 24 Aug 2020 12:39:03 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7961220838; Mon, 24 Aug 2020 16:39:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598287143; bh=TFQLrnd/E0M/aKPZvow4lTZFI5KdHTF5ZWkw7zGVU2w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Hhm0B9G2bWMjWvbqOKEdnaUNwx+e3RlGUyIQ/QRyjdDKu3wjNgGB0fsgV954st049 /2CNfIpyz2J2RWXyftmSQl+t0DkmQjQw65MJ+sszyCrRZUNgA8L6poby38P7xOJ2ad ZJzfiUAL7Fs3NPZYpv6zXtSs5yeI6ba13ydmGlaE= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Stanley Chu , Avri Altman , Andy Teng , "Martin K . Petersen" , Sasha Levin , linux-scsi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: [PATCH AUTOSEL 4.19 13/21] scsi: ufs: Fix possible infinite loop in ufshcd_hold Date: Mon, 24 Aug 2020 12:38:37 -0400 Message-Id: <20200824163845.606933-13-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200824163845.606933-1-sashal@kernel.org> References: <20200824163845.606933-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stanley Chu [ Upstream commit 93b6c5db06028a3b55122bbb74d0715dd8ca4ae0 ] In ufshcd_suspend(), after clk-gating is suspended and link is set as Hibern8 state, ufshcd_hold() is still possibly invoked before ufshcd_suspend() returns. For example, MediaTek's suspend vops may issue UIC commands which would call ufshcd_hold() during the command issuing flow. Now if UFSHCD_CAP_HIBERN8_WITH_CLK_GATING capability is enabled, then ufshcd_hold() may enter infinite loops because there is no clk-ungating work scheduled or pending. In this case, ufshcd_hold() shall just bypass, and keep the link as Hibern8 state. Link: https://lore.kernel.org/r/20200809050734.18740-1-stanley.chu@mediatek.com Reviewed-by: Avri Altman Co-developed-by: Andy Teng Signed-off-by: Andy Teng Signed-off-by: Stanley Chu Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/ufs/ufshcd.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index bd21c9cdf8183..ff6912f9f49f7 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -1538,6 +1538,7 @@ static void ufshcd_ungate_work(struct work_struct *work) int ufshcd_hold(struct ufs_hba *hba, bool async) { int rc = 0; + bool flush_result; unsigned long flags; if (!ufshcd_is_clkgating_allowed(hba)) @@ -1569,7 +1570,9 @@ int ufshcd_hold(struct ufs_hba *hba, bool async) break; } spin_unlock_irqrestore(hba->host->host_lock, flags); - flush_work(&hba->clk_gating.ungate_work); + flush_result = flush_work(&hba->clk_gating.ungate_work); + if (hba->clk_gating.is_suspended && !flush_result) + goto out; spin_lock_irqsave(hba->host->host_lock, flags); goto start; } -- 2.25.1