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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 AFFE5C2BA83 for ; Mon, 10 Feb 2020 01:28:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 77ECE20715 for ; Mon, 10 Feb 2020 01:28:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="CupfhlXJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726961AbgBJB2r (ORCPT ); Sun, 9 Feb 2020 20:28:47 -0500 Received: from mail25.static.mailgun.info ([104.130.122.25]:54859 "EHLO mail25.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725943AbgBJB2r (ORCPT ); Sun, 9 Feb 2020 20:28:47 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1581298126; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=6vYe1GUkbL8Po1/pcPili8cJnCI9H8iOTlQ55WPbG+g=; b=CupfhlXJUiSTkLBZSlPI2/Rq8IjUttp0E1gxxyeCJcEOrBF6bK0tKcYUbLqswsZKKJxALxue 9iAVuMnvBRMfZbvf3T9BCjhs/RC6XXyGDU11kfGCuM2DXB3NvF13cnsPxeLStAkjfBjXv0i0 n7notg+Yyhx/smU1ieBAqopzfKM= X-Mailgun-Sending-Ip: 104.130.122.25 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by mxa.mailgun.org with ESMTP id 5e40b1c9.7fa2590d1bc8-smtp-out-n01; Mon, 10 Feb 2020 01:28:41 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id B4D85C447AB; Mon, 10 Feb 2020 01:28:39 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: cang) by smtp.codeaurora.org (Postfix) with ESMTPSA id 16FE7C433A2; Mon, 10 Feb 2020 01:28:38 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 10 Feb 2020 09:28:38 +0800 From: Can Guo To: Avri Altman Cc: asutoshd@codeaurora.org, nguyenb@codeaurora.org, hongwus@codeaurora.org, rnayak@codeaurora.org, linux-scsi@vger.kernel.org, kernel-team@android.com, saravanak@google.com, salyzyn@google.com, Alim Akhtar , "James E.J. Bottomley" , "Martin K. Petersen" , Matthias Brugger , Bean Huo , Stanley Chu , Bart Van Assche , Venkat Gopalakrishnan , Tomas Winkler , open list , "moderated list:ARM/Mediatek SoC support" , "moderated list:ARM/Mediatek SoC support" Subject: Re: [PATCH v7 5/8] scsi: ufs: Fix ufshcd_hold() caused scheduling while atomic In-Reply-To: References: <1580978008-9327-1-git-send-email-cang@codeaurora.org> <1580978008-9327-6-git-send-email-cang@codeaurora.org> Message-ID: <2c485ce3fac4d92ab3776daecc1af493@codeaurora.org> X-Sender: cang@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-02-06 18:28, Avri Altman wrote: > Hi, > >> >> The async version of ufshcd_hold(async == true), which is only called >> in queuecommand path as for now, is expected to work in atomic >> context, >> thus it should not sleep or schedule out. When it runs into the >> condition >> that clocks are ON but link is still in hibern8 state, it should bail >> out >> without flushing the clock ungate work. > > Fixes: f2a785ac2312 (scsi: ufshcd: Fix race between clk scaling and > ungate work) Sorry, missed this one, if another version is needed, I will add this line. >> >> Signed-off-by: Can Guo >> Reviewed-by: Hongwu Su >> Reviewed-by: Asutosh Das >> Reviewed-by: Bean Huo >> Reviewed-by: Stanley Chu >> --- >> drivers/scsi/ufs/ufshcd.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c >> index bbc2607..e8f7f9d 100644 >> --- a/drivers/scsi/ufs/ufshcd.c >> +++ b/drivers/scsi/ufs/ufshcd.c >> @@ -1518,6 +1518,11 @@ int ufshcd_hold(struct ufs_hba *hba, bool >> async) >> */ >> if (ufshcd_can_hibern8_during_gating(hba) && >> ufshcd_is_link_hibern8(hba)) { >> + if (async) { >> + rc = -EAGAIN; >> + hba->clk_gating.active_reqs--; >> + break; >> + } >> spin_unlock_irqrestore(hba->host->host_lock, >> flags); >> flush_work(&hba->clk_gating.ungate_work); >> spin_lock_irqsave(hba->host->host_lock, >> flags); > Since now the above code is shared in all cases, > Maybe find a more economical way to pack it? > > Thanks, > Avri > > There are only 2 of this same code pieces in ufshcd_hold() and located in different cases, meanwhile there can be fall through, I don't see a good way to pack it, can you suggest if you have any ideas? Regards, Can Guo. >> -- >> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora >> Forum, >> a Linux Foundation Collaborative Project