From patchwork Thu Jan 16 23:17:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 233714 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=unavailable 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 AC120C33CAF for ; Thu, 16 Jan 2020 23:43:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 819812073A for ; Thu, 16 Jan 2020 23:43:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579218205; bh=ine7E5qPQZUYkUIMnNrr2s/IxLjekYwCjQbUn8Tu5AU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jdlucPTya6PtxeWdKh1zGV9tCWva/5iIsFxJ0NQAWX+Q5dmLUrIGd4BbtJoAaSXqY GA1EHJEP7QGjZRQ7fm0f/KtBMZzakgdGBJt2NbInWkyxWtLE9empR45trxK8Wmh3/d 41eA95oO8rVuBdjKaM7fBIHifT2LPiE566m4hVrs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387875AbgAPXnU (ORCPT ); Thu, 16 Jan 2020 18:43:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:55230 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391199AbgAPXZd (ORCPT ); Thu, 16 Jan 2020 18:25:33 -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 ECD81206D9; Thu, 16 Jan 2020 23:25:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579217132; bh=ine7E5qPQZUYkUIMnNrr2s/IxLjekYwCjQbUn8Tu5AU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c6k+CsOgZbg/LZZjnKnKPP9cDU+Gr1NCd+dqPAxQLgy+ppQcB23rb2n1vgvK/9YMx NiJSaRGLqf4bJA0y1yUN2WRX/bveRuBcanyW0ZT99apNxu4LI3YB0VoNmoRm1/+36K cnBGSoI5o4vgvnmmXA67oqviJFLX5XtzJz/BYWgU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peng Fan Subject: [PATCH 5.4 144/203] tty: serial: pch_uart: correct usage of dma_unmap_sg Date: Fri, 17 Jan 2020 00:17:41 +0100 Message-Id: <20200116231757.538548742@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200116231745.218684830@linuxfoundation.org> References: <20200116231745.218684830@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 @@ -233,6 +233,7 @@ 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; @@ -787,9 +788,10 @@ 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); } @@ -1010,6 +1012,7 @@ 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++) {