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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 21411C2D0DB for ; Wed, 22 Jan 2020 09:34:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E1AAE2467A for ; Wed, 22 Jan 2020 09:34:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579685687; bh=OYHLdzTv6DuN+cQWgdk2ujfLcH7pBy3HLUC/selvCJg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XRk5gJwtUnZulCgDQOCUZ16loiVytxTQ5Xhy26IdH5YS3y9TmgKApX/jH05Fxqxqm DxfmQzu79MUgfz3Z+7cZFJ9Qjcr82ppXsF7+ljoPeyQ+lFOYoBlcwT39MO6E3aOYZp 7OnsdlS2Va7wV8ArXra/ITKJgF2s0thnUS5ZMVQs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730992AbgAVJeq (ORCPT ); Wed, 22 Jan 2020 04:34:46 -0500 Received: from mail.kernel.org ([198.145.29.99]:49352 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730959AbgAVJen (ORCPT ); Wed, 22 Jan 2020 04:34:43 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1DAE82467B; Wed, 22 Jan 2020 09:34:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579685682; bh=OYHLdzTv6DuN+cQWgdk2ujfLcH7pBy3HLUC/selvCJg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IZ4oC94EP+Bpu8nfhLtADzqRZ8+GH92ICpLol4EKI7d0vzJH7gEJxuRL+2G21meh8 kNfyBsuNhPHT3TMCtLgRBZftf2dk7LTWPbnu1jgVgHEIHZqsrKh2tcEjIYqjVlN17T VwO6/+9exfFcX8Fmyn8Ip45QrT0yyi/c37NJuK3g= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peng Fan Subject: [PATCH 4.9 36/97] tty: serial: pch_uart: correct usage of dma_unmap_sg Date: Wed, 22 Jan 2020 10:28:40 +0100 Message-Id: <20200122092802.330819958@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200122092755.678349497@linuxfoundation.org> References: <20200122092755.678349497@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peng Fan commit 74887542fdcc92ad06a48c0cca17cdf09fc8aa00 upstream. Per Documentation/DMA-API-HOWTO.txt, To unmap a scatterlist, just call: dma_unmap_sg(dev, sglist, nents, direction); .. note:: The 'nents' argument to the dma_unmap_sg call must be the _same_ one you passed into the dma_map_sg call, it should _NOT_ be the 'count' value _returned_ from the dma_map_sg call. However in the driver, priv->nent is directly assigned with value returned from dma_map_sg, and dma_unmap_sg use priv->nent for unmap, this breaks the API usage. So introduce a new entry orig_nent to remember 'nents'. Fixes: da3564ee027e ("pch_uart: add multi-scatter processing") Signed-off-by: Peng Fan Link: https://lore.kernel.org/r/1573623259-6339-1-git-send-email-peng.fan@nxp.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/pch_uart.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/tty/serial/pch_uart.c +++ b/drivers/tty/serial/pch_uart.c @@ -252,6 +252,7 @@ struct eg20t_port { struct dma_chan *chan_rx; struct scatterlist *sg_tx_p; int nent; + int orig_nent; struct scatterlist sg_rx; int tx_dma_use; void *rx_buf_virt; @@ -806,9 +807,10 @@ static void pch_dma_tx_complete(void *ar } xmit->tail &= UART_XMIT_SIZE - 1; async_tx_ack(priv->desc_tx); - dma_unmap_sg(port->dev, sg, priv->nent, DMA_TO_DEVICE); + dma_unmap_sg(port->dev, sg, priv->orig_nent, DMA_TO_DEVICE); priv->tx_dma_use = 0; priv->nent = 0; + priv->orig_nent = 0; kfree(priv->sg_tx_p); pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_TX_INT); } @@ -1033,6 +1035,7 @@ static unsigned int dma_handle_tx(struct dev_err(priv->port.dev, "%s:dma_map_sg Failed\n", __func__); return 0; } + priv->orig_nent = num; priv->nent = nent; for (i = 0; i < nent; i++, sg++) {