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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 1D7E2C4360C for ; Mon, 19 Apr 2021 13:14:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F10C1613BC for ; Mon, 19 Apr 2021 13:14:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240043AbhDSNOd (ORCPT ); Mon, 19 Apr 2021 09:14:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:47554 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239880AbhDSNMv (ORCPT ); Mon, 19 Apr 2021 09:12:51 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 44DCD61288; Mon, 19 Apr 2021 13:12:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1618837922; bh=zbjn5UPooVYKlFNSLt2xYhyOKP05ZtgEEC6Y+7Iul5s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KFNVH+Qo2nIAV83QOWOkjQTfoEjfyfdokaQmDLGHGRMoWXQbTPpJzXTC6+NGpAd9J AQNJippamoCo9r2OK1P+PoJyuf2gEGbDrdNvyYPfyJB+udKwvdD2z4aXdTTiXSquyC f9N/zhE0RcZIvPvUMJSqYB49+nBuHuhZgab5guIg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Luo Jiaxing , John Garry , Jolly Shah , "Martin K. Petersen" Subject: [PATCH 5.11 067/122] scsi: libsas: Reset num_scatter if libata marks qc as NODATA Date: Mon, 19 Apr 2021 15:05:47 +0200 Message-Id: <20210419130532.464071114@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210419130530.166331793@linuxfoundation.org> References: <20210419130530.166331793@linuxfoundation.org> User-Agent: quilt/0.66 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: Jolly Shah commit 176ddd89171ddcf661862d90c5d257877f7326d6 upstream. When the cache_type for the SCSI device is changed, the SCSI layer issues a MODE_SELECT command. The caching mode details are communicated via a request buffer associated with the SCSI command with data direction set as DMA_TO_DEVICE (scsi_mode_select()). When this command reaches the libata layer, as a part of generic initial setup, libata layer sets up the scatterlist for the command using the SCSI command (ata_scsi_qc_new()). This command is then translated by the libata layer into ATA_CMD_SET_FEATURES (ata_scsi_mode_select_xlat()). The libata layer treats this as a non-data command (ata_mselect_caching()), since it only needs an ATA taskfile to pass the caching on/off information to the device. It does not need the scatterlist that has been setup, so it does not perform dma_map_sg() on the scatterlist (ata_qc_issue()). Unfortunately, when this command reaches the libsas layer (sas_ata_qc_issue()), libsas layer sees it as a non-data command with a scatterlist. It cannot extract the correct DMA length since the scatterlist has not been mapped with dma_map_sg() for a DMA operation. When this partially constructed SAS task reaches pm80xx LLDD, it results in the following warning: "pm80xx_chip_sata_req 6058: The sg list address start_addr=0x0000000000000000 data_len=0x0end_addr_high=0xffffffff end_addr_low=0xffffffff has crossed 4G boundary" Update libsas to handle ATA non-data commands separately so num_scatter and total_xfer_len remain 0. Link: https://lore.kernel.org/r/20210318225632.2481291-1-jollys@google.com Fixes: 53de092f47ff ("scsi: libsas: Set data_dir as DMA_NONE if libata marks qc as NODATA") Tested-by: Luo Jiaxing Reviewed-by: John Garry Signed-off-by: Jolly Shah Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/libsas/sas_ata.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) --- a/drivers/scsi/libsas/sas_ata.c +++ b/drivers/scsi/libsas/sas_ata.c @@ -201,18 +201,17 @@ static unsigned int sas_ata_qc_issue(str memcpy(task->ata_task.atapi_packet, qc->cdb, qc->dev->cdb_len); task->total_xfer_len = qc->nbytes; task->num_scatter = qc->n_elem; + task->data_dir = qc->dma_dir; + } else if (qc->tf.protocol == ATA_PROT_NODATA) { + task->data_dir = DMA_NONE; } else { for_each_sg(qc->sg, sg, qc->n_elem, si) xfer += sg_dma_len(sg); task->total_xfer_len = xfer; task->num_scatter = si; - } - - if (qc->tf.protocol == ATA_PROT_NODATA) - task->data_dir = DMA_NONE; - else task->data_dir = qc->dma_dir; + } task->scatter = qc->sg; task->ata_task.retry_count = 1; task->task_state_flags = SAS_TASK_STATE_PENDING;