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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C224C54EBE for ; Mon, 16 Jan 2023 16:06:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232171AbjAPQGC (ORCPT ); Mon, 16 Jan 2023 11:06:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43968 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232340AbjAPQFK (ORCPT ); Mon, 16 Jan 2023 11:05:10 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0EF9824492 for ; Mon, 16 Jan 2023 08:03:49 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id BB9F2B81060 for ; Mon, 16 Jan 2023 16:03:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1DE4EC433EF; Mon, 16 Jan 2023 16:03:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673885026; bh=qGoY/juyP+JW62BA6zmGEwNX9OuerpgTYnTvz5C/fCA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WoaOWIMrvu64RkssTDr2yQmcYciRRnNIQcgWDCe4tGBPsA+iB/fIbLRlogDGt4IEY zkLSfFhHPW/Bv08FfborOCkuFfIMJJNAIx7f5iNNV9vRsII8FRjSjk0+R2dQHqYiEw WKkOI3m8HN+OU4VR43vqoZzsoLH+EFTU7cwBl/FE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Bean Huo , Adrian Hunter , Bart Van Assche , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 5.15 47/86] scsi: ufs: Stop using the clock scaling lock in the error handler Date: Mon, 16 Jan 2023 16:51:21 +0100 Message-Id: <20230116154749.026889613@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230116154747.036911298@linuxfoundation.org> References: <20230116154747.036911298@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Bart Van Assche [ Upstream commit 5675c381ea51360b4968b78f23aefda73e3de90d ] Instead of locking and unlocking the clock scaling lock, surround the command queueing code with an RCU reader lock and call synchronize_rcu(). This patch prepares for removal of the clock scaling lock. Link: https://lore.kernel.org/r/20211203231950.193369-16-bvanassche@acm.org Tested-by: Bean Huo Reviewed-by: Adrian Hunter Reviewed-by: Bean Huo Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen Stable-dep-of: 1a5665fc8d7a ("scsi: ufs: core: WLUN suspend SSU/enter hibern8 fail recovery") Signed-off-by: Sasha Levin --- drivers/scsi/ufs/ufshcd.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index a428b8145dcc..6dd341674110 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -2700,6 +2700,12 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) if (!down_read_trylock(&hba->clk_scaling_lock)) return SCSI_MLQUEUE_HOST_BUSY; + /* + * Allows the UFS error handler to wait for prior ufshcd_queuecommand() + * calls. + */ + rcu_read_lock(); + switch (hba->ufshcd_state) { case UFSHCD_STATE_OPERATIONAL: case UFSHCD_STATE_EH_SCHEDULED_NON_FATAL: @@ -2766,7 +2772,10 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) } ufshcd_send_command(hba, tag); + out: + rcu_read_unlock(); + up_read(&hba->clk_scaling_lock); if (ufs_trigger_eh()) { @@ -5952,8 +5961,7 @@ static void ufshcd_err_handling_prepare(struct ufs_hba *hba) } ufshcd_scsi_block_requests(hba); /* Drain ufshcd_queuecommand() */ - down_write(&hba->clk_scaling_lock); - up_write(&hba->clk_scaling_lock); + synchronize_rcu(); cancel_work_sync(&hba->eeh_work); } -- 2.35.1