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,URIBL_BLOCKED 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 B1F68C2BB1D for ; Tue, 14 Apr 2020 06:14:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 76241206E9 for ; Tue, 14 Apr 2020 06:14:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="bPeaEors" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405839AbgDNGOr (ORCPT ); Tue, 14 Apr 2020 02:14:47 -0400 Received: from mail27.static.mailgun.info ([104.130.122.27]:18828 "EHLO mail27.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405829AbgDNGOm (ORCPT ); Tue, 14 Apr 2020 02:14:42 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1586844882; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=rzOJ+bED0a6EYmTfUhJM8iFUhrBMPXOs94qxa4YgxsM=; b=bPeaEorsTZ3LAFTNau+w5gqpqVezSrId75zvSpIa5e7LHDz6vbjasvTnwbSkRg9446z4Q6PN lSCLzdREcrPlp+ScjeQZhgtC/Ve5LPgpFQTkVVo4rhGSBsk14HLYG5DogL1Xf6wY3AIoz72V 6E8yIu61L4hzx+TRkxGCxg/DI1w= X-Mailgun-Sending-Ip: 104.130.122.27 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 5e9554c3.7f51e41080a0-smtp-out-n02; Tue, 14 Apr 2020 06:14:27 -0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 7D691C43636; Tue, 14 Apr 2020 06:14:26 +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 9BCA5C433CB; Tue, 14 Apr 2020 06:14:25 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Tue, 14 Apr 2020 14:14:25 +0800 From: Can Guo To: 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, cang@codeaurora.org Cc: "James E.J. Bottomley" , "Martin K. Petersen" , Stanley Chu , Alim Akhtar , Avri Altman , "Bean Huo (beanhuo)" , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/1] scsi: pm: Balance pm_only counter of request queue during system resume In-Reply-To: <1586841875-15667-1-git-send-email-cang@codeaurora.org> References: <1586841875-15667-1-git-send-email-cang@codeaurora.org> Message-ID: <9603edb9d1ae2c81dfd0a14bce4c6ce8@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 Loop more... On 2020-04-14 13:24, Can Guo wrote: > During system resume, scsi_resume_device() decreases a request queue's > pm_only counter if the scsi device was quiesced before. But after that, > if the scsi device's RPM status is RPM_SUSPENDED, the pm_only counter > is > still held (non-zero). Current scsi resume hook only sets the RPM > status > of the scsi device and its request queue to RPM_ACTIVE, but leaves the > pm_only counter unchanged. This may make the request queue's pm_only > counter remain non-zero after resume hook returns, hence those who are > waiting on the mq_freeze_wq would never be woken up. Fix this by > calling > blk_post_runtime_resume() if pm_only is non-zero to balance the pm_only > counter which is held by the scsi device's RPM ops. > > (struct request_queue)0xFFFFFF815B69E938 > pm_only = (counter = 2), > rpm_status = 0, > dev = 0xFFFFFF815B0511A0, > > ((struct device)0xFFFFFF815B0511A0)).power > is_suspended = FALSE, > runtime_status = RPM_ACTIVE, > > (struct scsi_device)0xffffff815b051000 > request_queue = 0xFFFFFF815B69E938, > sdev_state = SDEV_RUNNING, > quiesced_by = 0x0, > > B::v.f_/task_0xFFFFFF810C246940 > -000|__switch_to(prev = 0xFFFFFF810C246940, next = 0xFFFFFF80A49357C0) > -001|context_switch(inline) > -001|__schedule(?) > -002|schedule() > -003|blk_queue_enter(q = 0xFFFFFF815B69E938, flags = 0) > -004|generic_make_request(?) > -005|submit_bio(bio = 0xFFFFFF80A8195B80) > > Signed-off-by: Can Guo > > Change since v1: > - Added more debugging context info > > --- > drivers/scsi/scsi_pm.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c > index 3717eea..4804029 100644 > --- a/drivers/scsi/scsi_pm.c > +++ b/drivers/scsi/scsi_pm.c > @@ -93,8 +93,10 @@ static int scsi_dev_type_resume(struct device *dev, > */ > if (!err && scsi_is_sdev_device(dev)) { > struct scsi_device *sdev = to_scsi_device(dev); > - > - blk_set_runtime_active(sdev->request_queue); > + if (blk_queue_pm_only(sdev->request_queue)) > + blk_post_runtime_resume(sdev->request_queue, 0); > + else > + blk_set_runtime_active(sdev->request_queue); > } > }