From patchwork Tue Apr 14 05:24:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Can Guo X-Patchwork-Id: 11486807 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 39C83913 for ; Tue, 14 Apr 2020 05:24:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 221D72072D for ; Tue, 14 Apr 2020 05:24:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405482AbgDNFYj (ORCPT ); Tue, 14 Apr 2020 01:24:39 -0400 Received: from labrats.qualcomm.com ([199.106.110.90]:27979 "EHLO labrats.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726552AbgDNFYi (ORCPT ); Tue, 14 Apr 2020 01:24:38 -0400 IronPort-SDR: cwVzQoT1a708KngoN6/rGhZ6Goc8X6sBW3XGm5tzr0FZOeyHoFcHrELRpDi4BOEi1N0idHz+Vt gBtYgQDR26w/pzWrL2X0D7kBSUOAsBxZw5iSk+s5I9918FJ8YXBJgcOqypDacKYT1twNQPd86L aC2H8hZa5B2/CyxzxGgIFJKIu//jbdb1zFHQw05Rl+0lRwBVUEaLXV8iR5dtkdRxDkBCTOurTq ywwuYWCejNDmweW0QR//0xeGP84mQrcNlxJHX0U8kz7aaaH2yiBM/nhKBXMyEkeOGlCrkb7P37 Gvo= X-IronPort-AV: E=Sophos;i="5.72,381,1580803200"; d="scan'208";a="46834635" Received: from unknown (HELO ironmsg02-sd.qualcomm.com) ([10.53.140.142]) by labrats.qualcomm.com with ESMTP; 13 Apr 2020 22:24:37 -0700 Received: from pacamara-linux.qualcomm.com ([192.168.140.135]) by ironmsg02-sd.qualcomm.com with ESMTP; 13 Apr 2020 22:24:36 -0700 Received: by pacamara-linux.qualcomm.com (Postfix, from userid 359480) id 000D03B21; Mon, 13 Apr 2020 22:24:36 -0700 (PDT) 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" , linux-kernel@vger.kernel.org (open list) Subject: [PATCH v2 1/1] scsi: pm: Balance pm_only counter of request queue during system resume Date: Mon, 13 Apr 2020 22:24:34 -0700 Message-Id: <1586841875-15667-1-git-send-email-cang@codeaurora.org> X-Mailer: git-send-email 1.9.1 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org 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); } }