From patchwork Tue Nov 17 16:58:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jaegeuk Kim X-Patchwork-Id: 327768 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI,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 ACA90C64E90 for ; Tue, 17 Nov 2020 16:59:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5BAD824655 for ; Tue, 17 Nov 2020 16:59:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="xL4AkxbT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728324AbgKQQ6r (ORCPT ); Tue, 17 Nov 2020 11:58:47 -0500 Received: from mail.kernel.org ([198.145.29.99]:43794 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728107AbgKQQ6r (ORCPT ); Tue, 17 Nov 2020 11:58:47 -0500 Received: from localhost (unknown [104.132.1.66]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 849F124654; Tue, 17 Nov 2020 16:58:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605632326; bh=/Y3fTCys3yzpm1PjIxGpKZqD03qS2AZ/fgmi/1y720w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xL4AkxbT0Fr8LU6PueJPit6Zh255FDOV8oaZo+q9fL9yjNemadmgJk6mDDK0Mw3Fl T1rFpMm1Wq6aYzbitnUw6MC3fsDy1skpJIque8Ok+hCaR+IsRsxTyKKCwPdq6tufRs LIpEw/uIqPQE6EhKKmgL7jVzT119C5XLbo6NriFA= From: Jaegeuk Kim To: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, kernel-team@android.com Cc: cang@codeaurora.org, alim.akhtar@samsung.com, avri.altman@wdc.com, bvanassche@acm.org, martin.petersen@oracle.com, stanley.chu@mediatek.com, Jaegeuk Kim Subject: [PATCH v5 2/7] scsi: ufs: atomic update for clkgating_enable Date: Tue, 17 Nov 2020 08:58:34 -0800 Message-Id: <20201117165839.1643377-3-jaegeuk@kernel.org> X-Mailer: git-send-email 2.29.2.299.gdc1121823c-goog In-Reply-To: <20201117165839.1643377-1-jaegeuk@kernel.org> References: <20201117165839.1643377-1-jaegeuk@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Jaegeuk Kim When giving a stress test which enables/disables clkgating, we hit device timeout sometimes. This patch avoids subtle racy condition to address it. Note that, this requires a patch to address the device stuck by REQ_CLKS_OFF in __ufshcd_release(). The fix is "scsi: ufs: avoid to call REQ_CLKS_OFF to CLKS_OFF". Signed-off-by: Jaegeuk Kim --- drivers/scsi/ufs/ufshcd.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index cc8d5f0c3fdc..6c9269bffcbd 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -1808,19 +1808,19 @@ static ssize_t ufshcd_clkgate_enable_store(struct device *dev, return -EINVAL; value = !!value; + + spin_lock_irqsave(hba->host->host_lock, flags); if (value == hba->clk_gating.is_enabled) goto out; - if (value) { - ufshcd_release(hba); - } else { - spin_lock_irqsave(hba->host->host_lock, flags); + if (value) + __ufshcd_release(hba); + else hba->clk_gating.active_reqs++; - spin_unlock_irqrestore(hba->host->host_lock, flags); - } hba->clk_gating.is_enabled = value; out: + spin_unlock_irqrestore(hba->host->host_lock, flags); return count; }