From patchwork Thu Jun 1 15:56:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kai-Heng Feng X-Patchwork-Id: 688139 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 96AF4C7EE2A for ; Thu, 1 Jun 2023 15:57:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234303AbjFAP5y (ORCPT ); Thu, 1 Jun 2023 11:57:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56668 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234084AbjFAP5x (ORCPT ); Thu, 1 Jun 2023 11:57:53 -0400 Received: from smtp-relay-canonical-1.canonical.com (smtp-relay-canonical-1.canonical.com [185.125.188.121]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 92617134; Thu, 1 Jun 2023 08:57:51 -0700 (PDT) Received: from localhost.localdomain (unknown [10.101.196.174]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-canonical-1.canonical.com (Postfix) with ESMTPSA id A20C641795; Thu, 1 Jun 2023 15:57:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1685635070; bh=DhRFpLZy2hfyDYD8yUQHlqkoTRIcIzEoR9HeLiZfc8o=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=ZB5QNLujNDq3B3ALtV9mHbJwDV0D6Gc0PJfypM5wZYljiX8OB8kkvlJ8HTtqCOk9O QNqLgOkcnDjiP0Q5b0pDDfe5ALUWcH9JEeIgvbZsgIaJ+XJ+6EWzn1h4RWi5k/oV5T PKzvxp241OFnxXfMj8WBR/S8FPSlx5RHz0paftwOcUJkO9GhZRKy8Yppk309mvXTcG uQzelo2SEQ3vtb0J3ekC7qL8lkKpm7IFbb29ZPeg4/czSp7FVBCtoyj84QSlZ8XMaX BvCkK6UQVfFiAMv4HxR4467ReodYJW2xJoD9bZciZvxDcqlhBBpcXtImlp/XiPHlkn zK4eXONY/TBPA== From: Kai-Heng Feng To: jejb@linux.ibm.com, martin.petersen@oracle.com Cc: dlemoal@kernel.org, bblock@linux.ibm.com, acelan.kao@canonical.com, linux-pm@vger.kernel.org, Kai-Heng Feng , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v5] scsi: core: Wait until device is fully resumed before doing rescan Date: Thu, 1 Jun 2023 23:56:52 +0800 Message-Id: <20230601155652.1157611-1-kai.heng.feng@canonical.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org During system resuming process, the resuming order is from top to down. Namely, the ATA host is resumed before disks connected to it. When an EH is scheduled while ATA host is resumed and disk device is still suspended, the device_lock hold by scsi_rescan_device() is never released so the dpm_resume() of the disk is blocked forerver, therefore the system can never be resumed back. That's because scsi_attach_vpd() is expecting the disk device is in operational state, as it doesn't work on suspended device. To avoid such deadlock, wait until the scsi device is fully resumed, before continuing the rescan process. Signed-off-by: Kai-Heng Feng --- v5: - Use a different approach. Wait until the disk device is resumed. v4: - No change. v3: - New patch to resolve undefined pm_suspend_target_state. v2: - Schedule rescan task at the end of system resume phase. - Wording. drivers/scsi/scsi_scan.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index d217be323cc6..a59aada98ac5 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -1621,6 +1621,9 @@ void scsi_rescan_device(struct device *dev) { struct scsi_device *sdev = to_scsi_device(dev); + if (dev->power.is_suspended) + wait_for_completion(&dev->power.completion); + device_lock(dev); scsi_attach_vpd(sdev);