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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 BB05FC432C3 for ; Fri, 15 Nov 2019 07:03:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9382B2073B for ; Fri, 15 Nov 2019 07:03:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="NyUEhUv8"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="iATKS7ia" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727077AbfKOHDj (ORCPT ); Fri, 15 Nov 2019 02:03:39 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:58582 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726717AbfKOHDj (ORCPT ); Fri, 15 Nov 2019 02:03:39 -0500 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id E06AD61069; Fri, 15 Nov 2019 07:03:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1573801418; bh=cXKB7/z8hKIcCs1csnbwGGQvhJZYZrYw+Be56PBlCDI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=NyUEhUv8ts/nDu7Q0ClZ8xWYm4i9KztgjtFhp/gP9xiBba/jknAtjhEppiq592i2B HDJUwjlAc6etxqE+O32/g0egtG28sgeG5UNzu8J/ZJbj5wR76MZyJ23sww9zO1U3Xx m4nYgR7vbhlwsBvulvgjD8uSf8WZig3/aljjTCLw= Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id B18CE60F79; Fri, 15 Nov 2019 07:03:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1573801417; bh=cXKB7/z8hKIcCs1csnbwGGQvhJZYZrYw+Be56PBlCDI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=iATKS7iaEVRZOR1zD2uYbDqyi9VL7LHTyD+b44EEKNeZQoyLmbL/NK64TBzFlXNz6 t/BFWUgmCcUsDhjGCHS3tjTPGEV9NHxjhcO5pM9V5KaKr1WaPKur+mZjRXFdvdGwyG eFCuCurus72s1f3Axmxtmxgo/UkJkw4MaMjml8Dk= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Fri, 15 Nov 2019 15:03:37 +0800 From: Can Guo To: Stanley Chu Cc: asutoshd@codeaurora.org, nguyenb@codeaurora.org, rnayak@codeaurora.org, linux-scsi@vger.kernel.org, kernel-team@android.com, saravanak@google.com, salyzyn@google.com, Alim Akhtar , Avri Altman , Pedro Sousa , "James E.J. Bottomley" , "Martin K. Petersen" , Bean Huo , Tomas Winkler , Venkat Gopalakrishnan , Bjorn Andersson , Arnd Bergmann , open list Subject: Re: [PATCH v5 3/7] scsi: ufs: Fix up auto hibern8 enablement In-Reply-To: <1573799728.4956.5.camel@mtkswgap22> References: <1573798172-20534-1-git-send-email-cang@codeaurora.org> <1573798172-20534-4-git-send-email-cang@codeaurora.org> <1573799728.4956.5.camel@mtkswgap22> Message-ID: <2a925548b8ead7c3b5ddf2d7bf3de05d@codeaurora.org> X-Sender: cang@codeaurora.org User-Agent: Roundcube Webmail/1.2.5 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On 2019-11-15 14:35, Stanley Chu wrote: > Hi Can, > > On Thu, 2019-11-14 at 22:09 -0800, Can Guo wrote: >> + if (hba->ahit != ahit) >> + hba->ahit = ahit; >> spin_unlock_irqrestore(hba->host->host_lock, flags); >> + if (!pm_runtime_suspended(hba->dev)) { > > Always do pm_runtime_get_sync() here could avoid possible racing? > > And thus AH8 could be enabled regardless of runtime status. > >> + pm_runtime_get_sync(hba->dev); >> + ufshcd_hold(hba, false); >> + ufshcd_auto_hibern8_enable(hba); >> + ufshcd_release(hba); >> + pm_runtime_put(hba->dev); >> + } >> } > > Thanks, > Stanley Hi Stanley, if !pm_runtime_suspended() is true, hba->dev's runtime status, other than RPM_ACTIVE, may be RPM_SUSPENDING or RPM_RESUMING. So, here for safty, do pm_runtime_get_sync() once before access registers, in case we hit corner cases in which powers and/or clocks are OFF. Thanks, Can Guo.